List of Ben 10 characters

• This table shows the recurring characters and the actors who have portrayed them throughout the franchise.
• A dark grey cell indicates the character was not in the series or film, or that the character's presence in the series or film has not yet been announced.
• A ^Y indicates an appearance as a younger version of a pre-existing character.
• A ^C indicates a cameo appearance.
• A ^P indicates an appearance in onscreen photographs only.
• A ^D indicates an appearance in deleted scenes only.
• A ^M indicates a motion-capture role.
• A ^U indicates an uncredited role.

  = Main cast

  = Recurring cast

  = Guest cast

• This table shows the recurring characters and the actors who have portrayed them throughout the franchise.
• A dark grey cell indicates the character was not in the series or film, or that the character's presence in the series or film has not yet been announced.
• A ^Y indicates an appearance as a younger version of a pre-existing character.
• A ^C indicates a cameo appearance.
• A ^P indicates an appearance in onscreen photographs only.
• A ^D indicates an appearance in deleted scenes only.
• A ^M indicates a motion-capture role.
• A ^U indicates an uncredited role.

Voiced by:

• Tara Strong – Ben 10 (2005), Ben 10: Ultimate Alien, Ben 10: Omniverse & Ben 10 (2016) (child)
• Yuri Lowenthal – Ben 10: Alien Force, Ben 10: Ultimate Alien, Ben 10: Omniverse & Ben 10 (2016) (teenager)

Portrayed by:

• Graham Phillips – Ben 10: Race Against Time
• Ryan Kelley – Ben 10: Alien Swarm

Benjamin Kirby “Ben” Tennyson is titular character and the main protagonist of the franchise. At the start of Ben 10, he is a 10-year-old boy^{[note 1]} from Bellwood who, during his summer vacation, discovers the Omnitrix, a prototype device that attaches to his wrist and allows him to transform into various aliens. He uses the Omnitrix to become a superhero while traveling across the USA. After the Omnitrix is destroyed at the end of Alien Force, Ben retrieves the Ultimatrix from Albedo and uses it as a replacement before Azmuth gives him the official Omnitrix.

Voiced by:

• Meagan Smith – Ben 10 (2005)
• Ashley Johnson – Ben 10: Alien Force, Ben 10: Ultimate Alien, & Ben 10: Omniverse
• Montserrat Hernandez – Ben 10 (2016)

Portrayed by:

• Haley Ramm – Ben 10: Race Against Time
• Galadriel Stineman – Ben 10: Alien Swarm

Gwen Tennyson is Ben's paternal cousin. She is skilled in martial arts and possesses innate magical abilities due to her Anodite heritage.^[3]

Voiced by:

• Paul Eiding – Ben 10 (2005), Ben 10: Alien Force, Ben 10: Ultimate Alien & Ben 10: Omniverse (adult)
• Adam Wylie – Ben 10 (2005) (child)
• Jason Marsden – Ben 10: Ultimate Alien (teenager)
• David Kaye  – Ben 10 (2016)

Portrayed by:

• Lee Majors – Ben 10: Race Against Time
• Barry Corbin – Ben 10: Alien Swarm

Max Tennyson is Ben and Gwen's paternal grandfather. He is 60 years old in the original series, 65 in Alien Force and the reboot, 66 in Ultimate Alien and Omniverse, 80 in Ben 10,000 and 92 in Ken 10.^{[note 2]} Despite his age, he is shown to be a capable fighter, and after Ben finds the Omnitrix, supports him any way he can. Max was once a candidate for the Apollo 11 mission and one of the leaders, or "Magisters", of the Plumber organization, but Ben and Gwen did not know of this at first, believing him to have been a literal plumber.

Kevin Levin (voiced by Michael Reisz in the original series episode "Kevin 11", Charlie Schlatter in later episodes of the original series, and Greg Cipes in subsequent series; portrayed by Nathan Keyes in Alien Swarm) is a mutant human who can absorb matter, energy, and DNA and initially appears in the original series as an 11-year-old^{[note 3]} boy and one of Ben's enemies. However, he later reforms and becomes Ben's best friend and Gwen's love interest.^[4]

In the reboot series, He lacks powers and instead wields the Antitrix, a duplicate of the Omnitrix that Vilgax helped him build. The Antitrix aliens are corrupted versions of the Omnitrix aliens who are spliced with DNA of other unidentified species.

Rook Blonko (voiced by Bumper Robinson) is a Revonnahgander Plumber who Max assigns to work with Ben after Gwen and Kevin leave Bellwood for college. Rook is a top Plumber Academy graduate and skilled fighter who wields the Proto-tool, a shapeshifting weapon that can transform into various tools.^[5]

Kai Green (voiced by Bettina Bush) is a Native American and one of Ben's love interest. In a potential future depicted in Omniverse, Ben and Kai are married and have a son named Kenny.

The Plumbers are an intergalactic police force. While some work on Earth, most work in different parts of the universe.

Among the known Plumbers are:

• Magister Labrid (voiced by Jeff Bennett) is an Aquarian Plumber who recruited Max into the group. In the Alien Force pilot episode "Ben 10 Returns", Labrid is killed in battle with the Forever Knights.
• Magister Prior Gilhil (voiced by J. K. Simmons) is Max Tennyson's superior and the guardian of several hundred planets. He is later killed by Aggregor.
• Magister Patelliday (voiced by Rob Paulsen) is a Pisciss Volann Plumber and the second-in-command of the Plumbers on Earth.
• Magister Hulka (voiced by Miguel Ferrer) is a drill instructor at the Plumbers' Academy.

This group is composed of the children of Plumbers, most of whom are superpowered alien-human hybrids.

Cooper (voiced by Cathy Cavadini in the original series, Corey Padnos in Alien Force, Chris Pratt in Ultimate Alien, Eric Bauza in Omniverse) is a mutant human who can manipulate machines.

Alan Albright (voiced by Zeno Robinson in Alien Force and Ultimate Alien, Bumper Robinson in Omniverse) is a Pyronite hybrid who can return to his human form at will, unlike the other Plumbers' Helpers.

Helen Wheels (voiced by Juliet Landau) is a Kineceleran hybrid and friend of Manny. The two formerly hunted aliens before realizing their wrongs and reforming.

Manny Armstrong (voiced by Khary Payton) is a Tetramand hybrid and friend of Helen. The two formerly hunted aliens before realizing their wrongs and reforming.

Pierce Wheels (voiced by Adam Wylie) is a hybrid of Argit's species and Helen's adoptive brother. In Ultimate Alien, he is killed during the Forever Knights' purge of aliens on Earth.

Lucy Mann (voiced by Tara Strong) is a Lenopan, a slimy shapeshifting alien and Ben's cousin-in-law.

Julie Yamamoto (voiced by Vyvan Pham) is an Asian-American tennis player and one of Ben's love interests. She is commonly accompanied by Ship (also voiced by Pham), a dog-like Galvanic Mechamorph who can transform into a powered armor suit.

Azmuth (voiced by Robert David Hall in the original series, Jeff Bennett in Alien Force and Ultimate Alien, René Auberjonois in Omniverse, David Kaye in the reboot) is a Galvan and the creator of the Omnitrix. Furthermore, Galvan scientists under Azmuth's leadership accidentally created the Galvanic Mechamorphs during an experiment.

Professor Paradox (voiced by David McCallum) is a scientist who was displaced from time following a portal accident and developed the ability to manipulate time. Paradox uses the Chrononavigator to traverse space and time, which initially appears in the series as a pocket watch.^[6]

J. Jonah "Jimmy" Jones (voiced by Scott Menville) is a fan of Ben who exposed his secret identity to the world in Ultimate Alien. He is named in reference to the Marvel Comics character J. Jonah Jameson.^[7]

Aggregor's prisoners (also called the Andromeda Five) are a group of aliens from the Andromeda Galaxy who Aggregor captured to absorb their powers and claim the Map of Infinity. They consist of the Orishan Bivalvan, the Prypiatosian-B P'andor, the Talpaedan Andreas, and the Amperi Ra'ad (all voiced by Dee Bradley Baker), and the Geochelone Aerio Galapagus (voiced by John DiMaggio).

Sir George (voiced by Peter Renaday) is an immortal knight who founded the Forever Knights to combat Dagon. In Ultimate Alien, he reunites the Knights to achieve this goal, but is killed after Dagon removes his immortality.

Glitch (voiced by Tara Strong) is a character originating from the reboot continuity and a human-Galvanic Mechamorph hybrid who was created after Ben used Upgrade to enhance the Omnitrix. He is initially trapped in the Omnitrix before Ben frees him in the episode "Innervasion". Vilgax kills Glitch in Ben 10 Versus the Universe: The Movie, though Phil promises to recover his remains and resurrect him. In a potential future depicted in the episode "Ben 10,010", Glitch is converted into a drone-like form dubbed Hitch.

Ken Tennyson (voiced by Tara Strong in the original series, Scott Menville in Omniverse) is Ben's future son. He initially wields a duplicate of the Omnitrix before he is grounded and has it taken away. Afterward, Ken obtains time-traveling technology from Professor Paradox and becomes Chrono Spanner.

Ben 23 (voiced by Tara Strong) is an alternate universe variant of Ben from Dimension 23 who became a misguided celebrity due to his version of Max dying early. He initially believes all aliens to be evil before the prime Ben convinces him otherwise. Additionally, his alien transformations are predominantly blue rather than green and have different names than the prime Ben.

Ben 10,000 (voiced by Fred Tatasciore in the original series and reboot, Sean Donnellan in Ultimate Alien, Judd Nelson in Omniverse) is the name of several alternate future versions of Ben. The Ultimate Alien version of Ben 10,000 can use alien powers without transforming, while the Omniverse Ben 10,000 wields the Biomnitrix, a pair of Omnitrices that can transform him into alien hybrids.^[8]

Gwen 10 (voiced by Meagan Smith in the original series, Ashley Johnson in Omniverse) is an alternate universe variant of Gwen who found the Omnitrix instead of Ben.

Cash and JT are Ben's old bullies from school. Cash is voiced by Dee Bradley Baker in the original series, Matt Levin in Alien Force and Ultimate Alien, and Roger Craig Smith in the reboot, and portrayed by Tyler Patrick Jones in Race Against Time. JT is voiced by Adam Wylie in the original series, Scott Menville in Alien Force and Ultimate Alien, and Max Mittelman in the reboot, and portrayed by Tyler Foden in Race Against Time.

Lt. Steel (voiced by Michael Gough in the original series, Yuri Lowenthal in Omniverse) is the leader of SECT, a task force that deals with alien criminals.

Tetrax Shard (voiced by Dave Fennoy in the classic continuity, Todd Haberkorn in the reboot) is a Petrosapien and former mercenary. He inadvertently helped Vilgax destroy Petropia, causing him immense guilt until the planet is restored in the Alien Force episode "The Secret of Chromastone".

In the reboot, Tetrax is unaffiliated with Vilgax. He initially works with Kraab and SixSix before separating from them, with Kraab ripping off his left arm in a later fight.

Xylene (voiced by Grey DeLisle) is an Uxorite and friend of Max who sent the Omnitrix to Earth.

The Galactic Enforcers are a group of alien heroes. They consist of the Superman-like Ultimos (voiced by Tom Kane in the original series and Jeff Bennett in Alien Force), Synaptak (voiced by Greg Ellis), a psychic squid; and Tini (voiced by Vanessa Marshall in the original series and Juliet Landau in Alien Force), a Tetramand.

Myaxx (voiced by Vanessa Marshall in the original series, Vyvan Pham in Alien Force) is a Chimera Sui Generis and Azmuth's former assistant.

Carl Tennyson (voiced by Dee Bradley Baker in the original series, Don McManus in Alien Force and Race Against Time, Yuri Lowenthal in Ultimate Alien) and Sandra Tennyson (voiced by Tara Strong in the original series, Vyvan Pham and Beth Littleford in Alien Force, and Littleford alone in subsequent series) are Ben's parents. In Alien Force, Carl and Sandra punished Ben for using the Omnitrix until that they found out that Ben is trying to protect the world. In Ultimate Alien, Sandra is quite fit as she has been seen exercising with a fitness ball while Carl has gone out to pick up a new grow lamp.

Baz-El (voiced by Rob Paulsen) is a Galvanic Mechamorph and Ship's father.

Verdona (voiced by Juliet Landau in her Anodite form, Barbara Bain in her human form) is Ben and Gwen's Anodite grandmother.

Frank Tennyson (voiced by George Newbern) is Gwen's father.

Natalie Tennyson (voiced by Juliet Landau) is Gwen's mother.

Reinrassig III (voiced by Richard McGonagle) is a Highbreed officer who later becomes the leader of the Highbreed. Ben gives Reinrassig a Methanosian arm after he loses it on the planet Turrawuste, causing him to be unaffected by Ben rewriting the genetic code of the other Highbreed.

Elena Valadis (portrayed by Alyssa Diaz in Alien Swarm, voiced by Tia Texada in Ultimate Alien) is Victor Valadis' daughter, who becomes the queen of the Microchips after they possess her.

Victor Valadis (portrayed by Herbert Sigüenza in Alien Swarm, voiced by Brian George in Ultimate Alien) is a former Plumber and Elena's father.

Colonel Rozum (voiced by John DiMaggio) is an Air Force officer and a colleague of Max Tennyson.

The Unitrix (voiced by Molly C. Quinn) is a prototype version of the Omnitrix that can replicate animal abilities. It obtains a humanoid form dubbed Eunice after absorbing Gwen's DNA.

Ignacius Baumann (voiced by Richard Doyle in Ultimate Alien, Corey Burton in Omniverse) is a storekeeper who sells alien provisions. He is the subject of a running gag where Ben accidentally destroys his businesses. In the Omniverse episode "The Ballad of Mr. Baumann", Baumann marries Sheelane, a mermaid-like alien.

Zed (vocal effects provided by Paul Eiding) is an Anubian Baskurr and Khyber's former hunting dog, who Kevin adopts after Khyber abandons her. She formerly wielded the Nemetrix, an Omnitrix-like device that enabled her to transform into various predatory species. In the fourth season of Omniverse, Albedo upgrades the Nemetrix with an evolutionary feature similar to the Ultimatrix.

• Buglizard is a lizard-like alien and Stinkfly's predator. It has enhanced agility and sense of smell and can generate fog that melts Stinkfly's slime.
• Crabdozer is a rhinoceros/crab-like alien and Heatblast's predator. It has immense strength and fireproof rock-like skin.
• Hypnotick is a moth-like alien and Big Chill's predator. It is immune to intense cold and can become intangible and generate hypnotic mist that forces others to see visions of their greatest desires.
• Mucilator is a frog-like alien and Crashhopper's predator. It has immense strength and durability as well as adhesive sacs across its body.
• Omnivoracious is a ratite-like alien and Gray Matter's predator. It is highly intelligent, leading Galvans to be unable to outwit it. The Omnivoracious species became extinct long ago following a meteor strike, with Khyber obtaining Omnivoracious DNA from a fossil.
• Panuncian is a Smilodon-like alien and Ditto's predator. It is highly agile and possesses similar duplication abilities to its prey. Panuncian's Ultimate form is larger and possesses spiked armor. In the fourth season of Omniverse, Khyber obtains a Panuncian to act as a hunting dog after Zed abandons him.
• Slamworm is a worm-like alien and Armodrillo's predator. It can dig at high speeds and possesses acidic saliva and a sharp beak, both of which are adapted to destroy Talpaedan armor.
• Terroranchula is a tarantula-like alien and Ball Weevil's predator. It has sharp, powerful legs and can generate energy webs that destroy Insectoid slime.
• Tyrannopede is a dinosaur/insect-like alien and Humungousaur's predator. It has immense strength and durability and can generate webbing from its horn.
• Vicetopus is an octopus-like alien and Brainstorm's predator. It has a rubbery body that makes it elastic and resistant to electricity.

Pakmar (voiced by Tara Strong) is an alien shopkeeper who resides in Undertown. He is the subject of a running gag where Ben accidentally destroys his businesses.

Blarney Hokestar (voiced by Charlie Adler) is an alien con artist and smoothie seller.

Pax (voiced by Eric Bauza) is a Florauna animal lover and alien rights activist.

The Kraaho are hot-blooded tungsten-based aliens who thrive in warm temperatures.

Seebik (voiced by Corey Burton) is a thief and the former leader of the Kraaho.

Ester (voiced by Tara Platt) is the current leader of the Kraaho and one of Ben's love interests.

Hobble (voiced by Steve Blum) is an insect-like alien and a member of the Plumbers' Alpha Squad.

Rad Dudesman (voiced by Carlos Alazraqui) is a duck-like alien mercenary.

Pyxi (voiced by Carlos Alazraqui) is Rad's AI assistant.

Scout (voiced by Carlos Alazraqui) is a Loboan Plumber stationed in the Anur System.

Skurd (voiced by David Kaye) is a Slime-biot, a squid-like alien who can manipulate DNA. He assists Ben before leaving him to return to his creators, the Contumelia.

Heatblast (voiced by Steve Blum in the original series, David Franklin in Race Against Time, Dee Bradley Baker in Ultimate Alien, David Kaye in Omniverse, Daryl Sabara in the reboot) is a Pyronite, a fiery rock-based alien from the planet Pyros. He can generate and manipulate fire and fly by levitating rock.

WIldmutt (voiced by Dee Bradley Baker) is a Vulpimancer, a dog-like alien from the planet Vulpin. He is blind and incapable of speech, but has enhanced senses, including smell and hearing. Ultimate Wildmutt (also voiced by Baker) is red and capable of speech.

Diamondhead (voiced by Jim Ward in the original series, Daran Norris in Race Against Time, Dee Bradley Baker in Alien Force and Ultimate Alien, Eric Bauza in Omniverse, Roger Craig Smith in the reboot) is a Petrosapien, a humanoid silicon-based alien from the planet Petropia. He has a crystal-based body that enables him to generate crystals and transform his limbs into various weapons.

XLR8 (voiced by Jim Ward in the original series, Yuri Lowenthal in Omniverse, Josh Keaton in the reboot) is a Kineceleran, a raptor-like alien from the planet Kinet. He can move at superhuman speeds by lowering his own friction and create vortexes by running in circles.

Grey Matter (voiced by Richard Steven Horvitz in the original series, Carlos Alazraqui in Race Against Time, Eric Bauza in Omniverse, Todd Haberkorn in the reboot) is a Galvan, a frog-like alien from the planet Galvan Prime. He is small and physically weak, but has enhanced intelligence that makes him skilled with machines.

Four Arms (voiced by Richard McGonagle in the original series, Dee Bradley Baker in Ultimate Alien, John DiMaggio in Omniverse and the reboot) is a Tetramand, a red four-armed alien from the planet Khoros. He has immense strength and can create shockwaves by clapping his hands.

Stinkfly (voiced by Dee Bradley Baker in the classic continuity, Greg Cipes in the reboot) is a Lepidopterran, an insect-like alien from the planet Lepidopterra. He can fly at high speeds and generate adhesive slime with various properties. In the reboot, Stinkfly is redesigned to resemble a humanoid dragonfly.

Ripjaws (voiced by Fred Tatasciore in the original series, Eric Bauza in Omniverse) is a Pisciss Volann, a fish-like alien from the water planet Pisciss. He can swim at high speeds and possesses a powerful bite, but is incapable of surviving outside water.

Upgrade (voiced by Tara Strong in the original series, Yuri Lowenthal in Heroes United and Omniverse, David Sobolov in the reboot) is a Galvanic Mechamorph, a humanoid mechanical alien from the moon Galvan B. His body is made of nanites that enable him to reshape his body and possess technology.

Ghostfreak (voiced by Steve Blum in the original series and Omniverse, Jeff Bennett in Alien Force and Ultimate Alien) is an Ectonurite, a ghost-like alien from the planet Anur Phaetos. He has various abilities, including invisibility, intangibility, and possession. An Ectonurite's consciousness can exist even in a few strands of DNA, leading to the unique situation of a consciousness being trapped inside the Omnitrix.

Cannonbolt (voiced by Fred Tatasciore in the original series, Dee Bradley Baker in Alien Force and Ultimate Alien, David Kaye in Omniverse, Travis Willingham in the reboot) is an Arburian Pelarota, a pillbug-like alien from the destroyed planet Arburia. He can roll into a ball, making him nigh-invulnerable and enabling him to bounce at high speeds. Ultimate Cannonbolt (also voiced by Baker in Ultimate Alien) has a gray shell covered in spikes that he can shoot as projectiles.

Wildvine (voiced by Jim Ward in the original series, Dee Bradley Baker in Omniverse, David Hornsby in the reboot) is a Florauna, a humanoid plant-based alien from the planet Flors Verdance. He has an elastic body and can generate and manipulate plants.

Spitter (voiced by Dee Bradley Baker) is a Sphoeroid, a pufferfish-like alien from the planet Scalpasc. He can generate massive amounts of slime from his mouth.

Buzzshock (voiced by Tara Strong in the original series and reboot, Eric Bauza in Omniverse) is a Nosedeenian, a battery-like alien from the Nosideen Quasar. He can generate and manipulate electricity, enabling him to transform into energy and possess machines.

Arctiguana (voiced by Tom Kane in the original series, Eric Bauza in Omniverse) is a Polar Manzardill, a lizard-like alien from the planet X'Nelli. He can generate ice and fly by using it as propulsion. Arctiguana's Ultimate form (also voiced by Bauza in Omniverse), used by Albedo, is larger and possesses shoulder-mounted ice cannons.

Blitzwolfer (voiced by Tara Strong in the original series, Kevin Michael Richardson in Omniverse) is a Loboan, a werewolf-like alien from the moon Luna Lobo. He has enhanced physical abilities and can generate sonic howls by splitting his jaw.

Snare-oh (voiced by Richard Green in the original series, Kevin Michael Richardson in Omniverse) is a Thep Khufan, a mummy-like alien from the planet Anur Khufos. His body is made of elastic bandages, enabling him to stretch and disassemble his body at will.

Frankenstrike (voiced by Michael Dorn in the original series, David Kaye in Omniverse) is a Transylian, a Frankenstein monster-like alien from the planet Anur Transyl. He can generate electricity and control machinery via the plugs on his shoulders.

Upchuck (voiced by Dave Wittenberg in the original series, Dee Bradley Baker in Alien Force and Ultimate Alien, Eric Bauza in Omniverse) is a Gourmand, a reptilian alien from the planet Peptos XII. He has multiple prehensile tongues that enable him to ingest most forms of matter and expel it as energy projectiles.

Ditto (voiced by Rob Paulsen) is a Splixson, a mole-like alien from the planet Hathor. He is highly agile and can duplicate himself via binary fission.

Eye Guy (voiced by Dee Bradley Baker in the original series, Paul Eiding in Omniverse) is an Opticoid, a humanoid boneless alien from the planet Sightra. He has numerous eyes across his body from which he can project elemental beams.

Way Big (voiced by Fred Tatasciore in the original series, Dee Bradley Baker in Alien Force and Ultimate Alien, Eric Bauza in Omniverse, Roger Craig Smith in the reboot) is a To'kustar, a colossal humanoid alien that has no home planet and is born in cosmic storms. He has immense strength and can generate cosmic energy beams. His Ultimate form (also voiced by Baker in Ultimate Alien) has increased size and a red and blue color scheme, often regarded as an homage to Ultraman.

Eon (portrayed by Christien Anholt) is a Chronian, a humanoid alien from the planet Chronia. Eon forces Ben to transform into a Chronian to power the Hands of Armageddon.

Swampfire (voiced by Dee Bradley Baker) is a Methanosian, a plant-like humanoid from the planet Methanos. He can generate fire and manipulate plants. In Omniverse, Swampfire undergoes a puberty-like process, gaining enhanced abilities and a red and yellow color scheme.

Ultimate Swampfire (also voiced by Baker) resembles a tree and has blue napalm-like sacs across his body.

Echo Echo (voiced by Dee Bradley Baker) is a Sonorosian, a robot-like alien from the planet Sonorosia. He can duplicate himself and manipulate sound. His Ultimate form (also voiced by Baker) has the ability to fly and wields sonic discs that amplify his sound blasts, however is unable to duplicate.

Humungousaur (voiced by Dee Bradley Baker in Alien Force and Ultimate Alien, John DiMaggio in Omniverse, David Kaye in the reboot) is a Vaxasaurian, a dinosaur-like alien from the planet Terradino. He has immense size and strength and can grow further, up to a maximum of 60 feet. Ultimate Humungousaur (voiced by Baker in Alien Force and Ultimate Alien and DiMaggio in Omniverse) is green, has a spiked shell, and can shoot bony bullets from his hands.

Jetray (voiced by Dee Bradley Baker) is an Aerophibian, a manta ray-like alien from the planet Aeropela. He can fly at faster-than-light speeds and generate energy beams known as "neuroshocks".

Big Chill (voiced by Dee Bradley Baker) is a Necrofriggian, a moth-like alien from the planet Kylmyys. He can fly, generate ice, and become intangible. His Ultimate form (also voiced by Baker) is red and can generate plasma beams.

Chromastone (voiced by Dee Bradley Baker in Alien Force, Ultimate Alien, and the reboot, Eric Bauza in Omniverse) is a Crystalsapien, a humanoid crystal-based alien from the planet Petropia. Crystalsapiens are a unique species with only one member, Sugilite, who protects Petropia. Chromastone can manipulate and redirect energy as rainbow blasts.

Brainstorm (voiced by Dee Bradley Baker in Alien Force and Ultimate Alien, Corey Burton in Omniverse) is a Cerebrocrustacean, a crab-like alien from the planet Encephalonus IV. He is highly intelligent and can generate electricity, enabling him to levitate himself and others.

Spidermonkey (voiced by Dee Bradley Baker) is an Arachnichimp, an alien from the planet Aranhascimmia who resembles a monkey with multiple arms and eyes. He is highly agile and can generate large amounts of webbing. Ultimate Spidermonkey (voiced by Baker in Ultimate Alien and Paul Eiding in Omniverse) resembles a large purple gorilla with spider legs and can generate webs from his mouth.

Goop (voiced by Dee Bradley Baker) is a Viscosian, a humanoid slime-based alien from an unidentified planet. He has a malleable, slime-like body with shapeshifting capabilities and can generate acid. Goop uses his Anti-Gravity Projector to be fully mobile on planets that have gravity.

Alien X (voiced by Yuri Lowenthal in the classic continuity, Fred Tatasciore in the reboot) is a Celestialsapien, a humanoid alien from the Forge of Creation, a region outside the universe. Alien X has vast reality-warping abilities coupled with two split personalities: Bellicus (voiced by Kevin Conroy in Alien Force, Jeff Bennett in Alien Force: Vilgax Attacks and Ultimate Alien, and Eric Bauza in Omniverse) and Serena (voiced by Vicki Lewis in Alien Force, Tara Strong in Ultimate Alien, and Kimberly Brooks in Omniverse), who prevent him from acting until Ben convinces them to. Theoretically, Alien X possesses limitless power, as any thought Alien X conceives can be transformed into reality if all split personalities agree. Alien X is widely considered as the most powerful transformation within the Omnitrix.

Lodestar (voiced by Dee Bradley Baker) is a Biotsavartian, a humanoid metallic alien from the planet Maxwell. He can manipulate magnetism, enabling him to levitate objects and fly by magnetizing himself.

Rath (voiced by John DiMaggio in the classic continuity, Dee Bradley Baker in the reboot, and Bill Rogers in the video game Ben 10: Power Trip) is an Appoplexian, a tiger-like alien from the planet Appoplexia. He has immense strength and durability coupled with uncontrollable aggression. Ultimate Rath (also voiced by DiMaggio in Omniverse), used by Albedo, is larger and inspired by Marvel Comics character Kraven the Hunter.

Nanomech (voiced by Alex Winter in Alien Swarm, Dee Bradley Baker in Ultimate Alien and Omniverse) is a Microchip that was uniquely created by the Omnitrix. Unlike other Microchips, he has a humanoid, insect-like body due to being half-human and half-microchip. Nanomech can shrink to microscopic sizes and generate energy blasts from his eyes and hands.

Waterhazard (voiced by Dee Bradley Baker) is an Orishan, a mollusc-like alien from the planet Kiusana. He can manipulate pre-existing water, expel it as pressurized blasts, and fly by using water as propulsion.

Ampfibian (voiced by Dee Bradley Baker in Ultimate Alien and the reboot, Yuri Lowenthal in Omniverse) is an Amperi, a jellyfish-like alien from the planet Tesslos. He has various abilities, including electrokinesis, intangibility, and telepathy.

Armodrillo (voiced by Dee Bradley Baker in Ultimate Alien, John DiMaggio in Omniverse) is a Talpaedan, an armadillo-like alien from the planet Poiana Lüncas. He has drill-like arms that enable him to drill at high speeds and create shockwaves.

Terraspin (voiced by Dee Bradley Baker in Ultimate Alien, Bumper Robinson in Omniverse) is a Geochelone Aerios, a turtle-like alien from the planet Aldabra. He can generate powerful gusts of wind and fly by retracting his limbs and assuming a helicopter-like stance.

NRG (voiced by Dee Bradley Baker) is a Prypiatosian-B, an energy-based alien from the planet Prypiatos. He is highly radioactive and wears a containment suit to prevent his passive radiation from harming others. When NRG is outside of his containment suit his radioactive energy blasts and attacks are much more powerful and is able to fly.

Fasttrack (voiced by Dee Bradley Baker) is a Citrakayah, a cat-like alien from the planet Chalybeas. He can move at superhuman speeds, similar to XLR8.

Chamalien (voiced by Dee Bradley Baker) is a Merlinisapien, a chameleon-like alien from an unidentified planet. He is highly agile and can become invisible.

Eatle (voiced by Dee Bradley Baker in Ultimate Alien, Eric Bauza in Omniverse) is an Oryctini, a beetle-like alien from the planet Coleop Terra. Similar to Upchuck, Eatle is able to ingest all sorts of different material and converts that into energy beams.

Clockwork (voiced by Dee Bradley Baker) is a Chronosapien, a robotic alien from an unidentified planet. He can manipulate time, enabling him to rapidly age others and view the past. Furthermore, Clockwork has the ability to slow down time around him while still being able to move at a regular speed, making it appear to others as though he is moving extremely rapid.

Juryrigg (voiced by Dee Bradley Baker in Ultimate Alien, Bumper Robinson in Omniverse) is a Planchaküle, a gremlin-like alien from the planet Aul-Turrhen. He has innate engineering abilities and can disassemble and reassemble machinery into new forms.

Shocksquatch (voiced by David Kaye) is a Gimlinopithecus, a yeti-like alien from the planet Pattersonea. He can generate and manipulate electricity, enabling him to shield himself from radiation.

Feedback (voiced by Yuri Lowenthal) is a Conductoid, a black humanoid alien from the Teslavorr Nebula. He has plug-like fingers and long antennae that enable him to absorb and redirect energy.

Bloxx (voiced by Bumper Robinson in Omniverse, David Kaye in the reboot) is a Segmentasapien, a primate-like alien from the planet Polyominus. He has an elastic body made of Lego-like bricks that can form various constructs and be shot as projeciles.

Gravattack (voiced by David Kaye) is a Galilean, a planet-like alien from the planet Keplorr. He can fly and manipulate gravity, enabling him to levitate himself and others. Ultimate Gravattack (also voiced by Kaye), used by Albedo, has three smaller planetoids orbiting him and lacks legs.

Crashhopper (voiced by Dee Bradley Baker) is an Orthopterran, a grasshopper-like alien from an unidentified planet. He has powerful legs that enable him to jump far and create shockwaves upon landing.

Ball Weevil (voiced by Bumper Robinson) is an Insectoid, an insect-like alien from the planet Atrocious 0. He can generate adhesive balls of slime that can absorb matter and grow in size.

Walkatrout (voiced by Yuri Lowenthal) is an Ickthyperambuloid, a fish-like alien from the planet Gilli-Perambulous Promenade. He is physically weak, with his only power being slippery skin that makes him agile and difficult to grab.

Pesky Dust (voiced by Tara Strong) is a Nemuina, a fairy-like alien from the planet Nemuinos IV. He can fly and generate dust that enables him to put others to sleep and manipulate their dreams.

Mole-Stache (voiced by David Kaye) is an unidentified mole-like alien from an unidentified planet. He has a prehensile mustache that can act as fists and enables him to fly by spinning like a helicopter.

The Worst (voiced by Dee Bradley Baker) is an Atrocian, a rotund alien from the planet Atrocian. He is highly durable and virtually indestructible, but is not immune to pain.

Kickin Hawk (voiced by Yuri Lowenthal) is an unidentified bird-like alien from an unidentified planet. He is highly skilled in hand-to-hand combat and has sharp blades on his elbows.

Toepick (voiced by Eric Bauza) is an unidentified ogre-like alien from an unidentified planet. He has a terrifying face that can incapacitate others, which is usually covered by a cage-like helmet.

Astrodactyl (voiced by Dee Bradley Baker) is an unidentified Pterosaur-like alien from an unidentified planet. He is able to fly at high speeds and can generate and manipulate stellar energy.

Bullfrag (voiced by John DiMaggio) is an Incursean, a frog-like alien from an unidentified destroyed planet. He is highly agile and has a prehensile tongue. Bullfrag is extremely sensitive to strong odors.

Atomix (voiced by John DiMaggio) is an unidentified robotic alien from an unidentified planet. He has immense strength and can generate radiation.

Gutrot (voiced by Rob Paulsen) is an unidentified robotic alien from an unidentified planet. He has a large, transparent stomach that enables him to create various forms of gas.

Whampire (voiced by John DiMaggio) is a Vladat, a vampire-like alien from the planet Anur Vladias. He can drain life force and hypnotize others using bat-like parasites called Corrupturas.

Overflow (voiced by Max Mittelman) is a Cascan, a water-based alien from the planet Cascareau. He has a similar appearance and powers to Waterhazard.

Gax (voiced by Yuri Lowenthal) is a Chimera Sui Generis, a squid-like alien of the same species as Vilgax. Ben loses access to Gax after Vilgax steals his DNA to regain his full strength.

Shock Rock (voiced by David Kaye) is a Fulmini, an energy-based alien from the destroyed planet Fulmas. He can generate and manipulate electricity. Furthermore, Shock Rock's presence in the Omnitrix influences the other Omnitrix aliens and gives them additional electricity-based abilities similar to his.

Slapback (voiced by Todd Haberkorn) is an Ekoplektoid, a frog-like alien from the planet Ekoplekton. He can duplicate when struck on the back, with clones progressively gaining increases strength and density.

Surge (voiced by Fred Tatasciore) is a Xerge, a robotic X-shaped alien from an unidentified planet. He is powerless on his own, but can link with other Xerge to create constructs.

Vilgax (voiced by Steve Blum in the original series and Omniverse, James Remar in Alien Force and Ultimate Alien, Yuri Lowenthal in the reboot) is a Chimera Sui Generis warlord and Ben's archenemy.

Doctor Aloysius James Animo (voiced by Dwight Schultz) is the first human antagonist Ben faces in the series. Animo was once a promising researcher in veterinary scientist until his career was cut short when he was caught creating twisted genetic experiments. He thought that the experiment would earn him the Verities Award only to lose it to a scientist named Kelly. This drove him mad, causing him to disappear for five years until he could perfect his research.

SixSix (voiced by Dee Bradley Baker in the original series, Josh Keaton in the reboot) is a Sotoraggian bounty hunter and SevenSeven's brother.

Kraab (voiced by Billy West in the original series, Jeff Bennett in Alien Force, Dee Bradley Baker in Omniverse, Travis Willingham in the reboot) is a Piscciss Premann cyborg and bounty hunter.

Rojo (voiced by Jennifer Hale in the original series and Omniverse, Kari Wahlgren in Ultimate Alien) is a thief and gang leader. In the original series, she temporarily fuses with one of Vilgax's drones, giving her claws and shoulder-mounted lasers.

Herbert J. Zomboni or Zombozo (voiced by John Kassir in the original series, John DiMaggio in subsequent appearances) is a zombie-like clown who feeds on fear.

The Circus Freak Trio are a trio who worked together under the guise of freak show performers in Zombozo's circus before his disappearance.

Acid Breath (voiced by Dee Bradley Baker in the classic continuity, Josh Keaton in the reboot) is a member of the Circus Freaks who can generate acid.

Frightwig (voiced by Cree Summer in the classic continuity, Jessica DiCicco in the reboot) is a member of the Circus Freaks who has prehensile, tentacle-like hair.

Thumbskull (voiced by Jeff Doucette in the original series, David Kaye in Omniverse, John DiMaggio in the reboot) is a member of the Circus Freaks who has superhuman strength and a nail-like horn.

Hex (voiced by Khary Payton in the classic continuity, Robin Atkin Downes in the reboot) is a sorcerer from Ledgerdomain and Charmcaster's uncle. In Omniverse, he reforms and becomes a professor at Friedkin University.

Phil Billings (voiced by Robert Patrick in the original series, Rob Paulsen in Omniverse, John DiMaggio in the reboot) is a corrupt former Plumber and partner of Max. In between the events of the original series and Omniverse, Khyber and Dr. Psychobos use Phil as a test subject for the Nemetrix, giving him the ability to transform into a Terroranchula hybrid.

In the reboot, Phil is a benevolent inventor who remains a member of the Plumbers.

The Forever Knights are a secret paramilitary organization dealing with alien encounters and other varying activities. They were founded by Sir George to fight Dagon, but his departure resulted in them splintering into factions, each led by a Forever King. During the events of Ultimate Alien, George reunites the Forever Knights to combat Dagon, during which most of them are killed.

The Forever Knights consist of Enoch (voiced by Richard Doyle), Driscoll (voiced by Richard Doyle), the Red Knight, Connor (voiced by Hakeem Kae-Kazim), Joseph Chadwick (voiced primarily by Tim Curry and by David Kaye in the Omniverse episode "Return to Forever"), Morton (voiced by Kevin Michael Richardson), Winston (voiced by Patrick Cavanaugh), Urian (voiced by Jim Piddock), and Cyrus (voiced by Robin Atkin Downes).

In the reboot, a lone Forever Knight (voiced by Roger Craig Smith) is featured as a major antagonist.

Clancy (voiced by Nicholas Guest) is a mutant human who can control insects. He later mutates further and becomes an insect-like monster.

Vulkanus (voiced by John DiMaggio) is a Detrovite criminal. His body was previously destroyed in an explosion, leaving only his head intact and forcing him to wear powered armor until his body regenerated.

Charmcaster (voiced by Kari Wahlgren in the classic continuity, Tara Strong in the reboot) is a sorceress from Ledgerdomain and Hex's niece. Her father Spellbinder was previously killed by Addwaitya, forcing her and Hex to flee to Earth.

Zs'Skayr (voiced by Steve Blum in the original series and Omniverse, Jeff Bennett in Alien Force) is the leader of Anur Phaetos and Ghostfreak's genetic donor. His consciousness is initially trapped in the Omnitrix before escaping in the original series episode "Ghostfreaked Out".

The Werewolf is an unnamed Loboan and a servant of Zs'Skayr.

The Mummy is an unnamed Thep Khufan and a servant of Zs'Skayr.

Dr. Viktor (voiced by Michael Dorn) is a Transylian scientist and Zs'Skayr's assistant.

Exo-Skull (voiced by Richard McGonagle in the original series, David Kaye in Omniverse) is a rhinoceros-like mutant created by Dr. Animo. Originally encountered in Ben 10,000's future in the original series, a present-day version of Exo-Skull is later seen in Omniverse as one of Maltruant's minions and the partner of Subdora.

Kane North (voiced by John Cygan in the original series, Corey Burton in Omniverse) is the creator of the television series Kangaroo Kommando and a criminal who wields a suit based on the series' eponymous character.

Eon (portrayed by Christien Anholt in Race Against Time, voiced by Yuri Lowenthal and Sean Donnellan in Ultimate Alien, Judd Nelson in Omniverse) is a time-travelling villain and rival of Professor Paradox. He is initially depicted as a Chronian before being retconned as an alternate universe variant of Ben.

Eon's Servants are the servants of Eon. They are depicted as corrupted humans in the original series and Ultimate Alien and as robots in Omniverse.

Atasians, commonly known as the Highbreed, are a xenophobic species from the planet Augstaka who serve as the initial primary antagonists of Alien Force. They are voiced by various actors, including Dee Bradley Baker, Paul Eiding, Robert David Hall, Richard McGonagle, and Kevin Michael Richardson.

The DNAliens are lifeforms infected by Xenocites, alien leeches created by the Highbreed. They are voiced by various actors, including Dee Bradley Baker, Jeff Bennett, Greg Cipes, Diane Delano, Paul Eiding, Will Friedle, Wallace Langham, and Richard McGonagle.

Gorvan (voiced by John DiMaggio in Alien Force, Rob Paulsen in Omniverse) is a Tetramand criminal. Gorvan is initially a traitorous Plumber who debuts in a tie-in video game to Alien Force, before reappearing as an ally of Psyphon in Omniverse.

Argit (voiced by Alexander Polinsky) is a rat-like alien con man and friend of Kevin. He possesses venomous quills that can paralyze anyone exposed to them. In Omniverse, he reforms and creates a security company.

Michael Morningstar (voiced by Wil Wheaton in the classic continuity, Drake Bell in the reboot episode "Bright Lights, Black Hearts", Yuri Lowenthal in the reboot episode "The Charm Offensive"), also known as Darkstar, is a mutant who can absorb life energy from others. He initially masquerades as benevolent before Ben exposes and defeats him, temporarily rendering him drained and zombie-like.

The Incurseans are toad-like aliens who were forced to become spacefarers after their planet was destroyed during a civil war.

Milleous (voiced by Kevin Michael Richardson in the classic continuity, Roger Craig Smith in the reboot) is Attea's father and the former leader of the Incurseans.

Attea (voiced by Tara Strong) is an Incursean princess and the daughter of Emperor Milleous, who she later seizes power from.

Raff (voiced by James Arnold Taylor in Alien Force, Eric Bauza in Omniverse) is a Sylonnoid commander who serves the Incurseans.

SevenSeven (voiced by Dee Bradley Baker) is a Sotoraggian bounty hunter and SixSix's brother.

Albedo (voiced by Eric Bauza in Galvan form, Yuri Lowenthal in human form) is a Ben's evil counterpart and Galvan and Azmuth's former assistant. He wields a copy of the Omnitrix that made his default form an albino clone of Ben.

The Queen (voiced by Wendy Cutler) is the queen of the Nanochips.

Psyphon (voiced by Dee Bradley Baker) is an alien and former servant of Vilgax who later becomes an independent criminal.

The R.E.D.s (Robotic Extermination Devices) are red robots who work for Psyphon.

Ssserpent (voiced by Dee Bradley Baker) is a snake-like alien criminal.

The Vreedle Brothers are Vreedle bounty hunters and the sons of Ma and Pa Vreedle. They consist of Octagon Vreedle (voiced by John DiMaggio) and Rhomboid Vreedle (voiced by Rob Paulsen).

Sunder (voiced by Powers Boothe in Alien Force and Ultimate Alien, David Kaye in Omniverse) is an alien bounty hunter who wields an axe.

Jarret (voiced by Alexander Polinsky) is the leader of the Pantophage.

Will Harangue (voiced by John DiMaggio) is a news anchor (a parody of J. K. Simmons' portrayal of J. Jonah Jameson^[7]) who believes Ben to be a menace. In Omniverse, he allies with the Incurseans before Ben transforms him into an alien using the Forever Knights' machine.

Aggregor (voiced by John DiMaggio) is an Osmosian who sought to obtain godhood by absorbing a baby Celestialsapien. He nearly succeeds, but is defeated by Kevin and imprisoned in the Null Void.

Carl Nesmith (voiced by Christopher McDonald) is a fraud and glory-hound who poses as the superhero Captain Nemesis and stages crimes to make himself look heroic.

Computron (voiced by Dee Bradley Baker) is a robotic villain who was imprisoned in Dimension 12.

Xarion (voiced by Peter Stormare) is the king of Zarkovia. He transfers his mind into Dr. Viktor's body in Ultimate Alien and is killed in Omniverse when Zs'Skayr destroys his soul.

Addwaitya (voiced by John DiMaggio in Ultimate Alien, Steve Blum in Omniverse) is a mutant Geochelone Aerios and sorcerer.

Pa Vreedle (voiced by Jeff Bennett in Ultimate Alien, Steve Blum in Omniverse) is Ma Vreedle's ex-husband and the father of the Vreedle Brothers.

Trumbipulor (voiced by Dee Bradley Baker in Ultimate Alien, Eric Bauza in Omniverse) is an elephant-like alien criminal.

Dagon (voiced by John DiMaggio) is an interdimensional squid-like entity who the Forever Knights were originally created to fight. At the end of Ultimate Alien, Dagon is imprisoned in the Sword of Ascalon and sent into space.

The Lucubra (voiced by Dee Bradley Baker) are animalistic servants of Dagon who feed on the thoughts of others.

The Flame Keeper's Circle is a cult that worships Dagon. They consist of Conduit Edwards (voiced by John DiMaggio) and the Esoterica, foot soldiers who can teleport between dimensions.

Ma Vreedle (voiced by Diane Delano) is a notorious criminal and the leader of the Vreedles. She is assisted by the Pretty Boy Vreedles, an army of mass-produced children (also voiced by Delano).

Inspector 13 (voiced by Dee Bradley Baker) is an illegal weapons dealer and a former Techadon Weaponmaster.

Malware (voiced by Corey Burton) is a mutant Galvanic Mechamorph who was born with an emaciated, yellow appearance and can absorb technology rather than enhance it. Frustrated by Azmuth's refusal to heal him, Malware steals the cure he created and assumes a monstrous red form.

Khyber (voiced by David Kaye) is a Zaroffian hunter who battles Ben out of a desire to find worthy prey.

Dr. Psychobos (voiced by Eric Bauza) is a cybernetically enhanced Cerebocrustacean who helped Khyber create the Nemetrix.

A group of criminal aliens that reside in Undertown. They are mainly hired by Psyphon for different plans, but also act independently to commit other criminal acts.

Bubble Helmet (voiced by John DiMaggio) is a caterpillar-like alien who wields powered armor that enables him to breathe.

Fistina (voiced by Morgan Lofting) is a cybernetically enhanced Acrosian who uses a containment suit as battle armor and can shoot her fists like rockets. Later in the series, she reforms and considers joining the Plumbers.

Liam (voiced by Paul Eiding) is a chicken-like alien of the same species as Kickin' Hawk.

Thunderpig (voiced by Eric Bauza) is a pig-like alien who wields an electrified flail. His design and name are a parody of ThunderCats.

Tummyhead (voiced by Rob Paulsen) is a two-headed alien who works for Psyphon.

Sweet-Eels Sparklefunk (voiced by Kevin Michael Richardson) is a tentacled alien who works for Psyphon.

Bouncer (voiced by Bumper Robinson) is an unnamed alien who works for Psyphon.

Bug-Lite (voiced by Bumper Robinson) is an insect-like alien who works for Psyphon.

Fistrick (voiced by Eric Bauza) is a crime lord and arms dealer. He is served by Corvo (voiced by Bumper Robinson), an unnamed Thug (voiced by Dee Bradley Baker in "A Jolt from the Past", Eric Bauza in "No Honor Among Bros"), and an unnamed Hoodlum (voiced by Paul Eiding in "A Jolt from the Past", Yuri Lowenthal in "No Honor Among Bros").

Solid Plugg (voiced by Eric Bauza) is a freelance criminal and resident of Undertown.

Looma Red Wind (voiced by Kimberly Brooks) is a Tetramand princess who Ben becomes betrothed to after defeating her in solo combat.

Billy Billions (voiced by Aziz Ansari in Omniverse, Gunnar Sizemore in the reboot) is a billionaire and childhood rival of Ben. He was previously trapped in Dimension 12 during a battle with Ben and rendered incapable of aging.

Mazuma (voiced by Tara Strong) is an android and Billy Billions' servant.

Nyancy Chan (voiced by Gwendoline Yeo) is a mutant criminal who can control felines.

EightEight (voiced by Dee Bradley Baker) is a Sotoraggian bounty hunter and the older sister of SevenSeven and SixSix.

The Way Bads (voiced by Eric Bauza) are mutant To'kustars created by Dr. Psychobos.

Crüjo (voiced by Bumper Robinson) is a bear-like Loboan who works for Zs'Skayr.

Kuphulu (voiced by Jeffrey Combs) is a Thep Khufan who works for Zs'Skayr.

Lord Transyl (voiced by David Kaye) is the former leader of the Vladats, who were killed in a war with the Transylians. In the present day, Zs'Skayr resurrects Transyl using the Alpha Rune.

The Rooters are a black ops unit of the Plumbers who transformed themselves into alien hybrids using Kevin's abilities. They consist of the Cerebrocrustacean hybrid Servantis (voiced by Charlie Adler), the Aerophibian hybrid Swift (voiced by Tara Strong), the silent Prypiatosian-B hybrid Leander, and Max's former partner Phil.

Kundo (voiced by Jeff Bennett) is a Revonnahgander traditionalist and Rook Blonko's former teacher who despises technology. He is later transformed into a cyborg after being mortally wounded in battle with Ben.

Maltruant (voiced by Mark Hamill) is an evil Chronosapien who seeks to remake the universe in his image. In the Omniverse series finale, "A New Dawn", he is defeated and trapped in a time loop that has him continually rebuilt and destroyed.

Subdora (voiced by Tara Platt) is a Merlinisapien thief who works for Maltruant and is partnered with Exo-Skull.