Casper and the Spectrals

In New York City, a young ghost named Casper and his cousin, Spooky, get lessons from their uncles, Lazo, Fusso and Fatso, as they demonstrate by scaring a human family on a subway train. However, Casper doesn't understand why, so at school in their homeworld of Spookytown, his uncles inform him that they must scare humans in order to keep a monstrous entity named Volbragg dormant. Casper assumes that he is a myth, but his uncles tell him the story of Willem Georges Volbragg, a tyrannical politician from the 1600s who wanted to rule New Amsterdam and terrorize the townspeople, but they sank him to the bottom of a river and left him for dead. Volbragg then ended up in Spookytown (where he became a demon) and decided to take it over by getting power from a witch, who was able to use the magic spells to collect the scares in Spookytown, which are converted into an energy source to destroy the race with the least scares. This led the more intelligent ghosts and witches, however, to start a plan to capture Volbragg and use his power to collect scares, imprisoning him, and they must continue channeling the scare energy.

Upset, Casper decides to fly around Spookytown while thinking of another way to keep Volbragg dormant instead of scaring humans. He spies on other races of monsters and sees a group of witches terrorizing a group of humans, until a young witch named Wendy interrupts, displeased with her aunts scaring humans for their amusement. She has all the humans disappear except for a young boy, who Casper unintentionally scares off and sends back home, causing Wendy to thank him. Seeing how she is similar to him, Casper befriends Wendy, and they spend time socializing and learning about one another.

One day in Deviland, they meet a trouble-making young devil named Hot Stuff who pulls a prank on a group of ogres and frames Casper and Wendy for it, leading the ogres to trap them in a net that is immune to their powers. Realizing his mistake, Hot Stuff decides to save them by impersonating a mud monster and demands the ogres to let them go before entrapping them with their net. After escaping, Casper and Wendy offer Hot Stuff to join them, which he reluctantly agrees to, and teach him to be nice, while Hot Stuff shows them his race of demons. The trio later encounters a werewolf, who attempts to eat Hot Stuff and finds Casper’s attempt to scare him amusing.

The trio leaves and goes to their treehouse hideout, only to be caught and punished by their furious elders, who forbid them to see each other again. Meanwhile, two scientists, Professor Phineas Field and his assistant, Eloise “Ellie” Essex, attempt to learn about the other world and collect its energy source, but the machine they use takes away their energy, releases the monsters into their world, and weakens Volbragg's prison, causing him to break free and terrorize Spookytown. Casper, Wendy, and Hot Stuff reunite and witness the chaos as the monsters flee from Volbragg, whom Casper believes is lonely and wants to be accepted, but Wendy and Hot Stuff say that it is a bad idea, leading to an argument between Casper and Wendy that ends their friendship and leaves Hot Stuff on his own. Hot Stuff then goes to meet Phineas and Ellie, who tell him about the incident, and flies off to find Casper and Wendy. Meanwhile, Wendy finds the witch who gave the spells to Volbragg who, in turn, gives Wendy her wand. Casper goes to reason with Volbragg, but is interrupted by Hot Stuff and Wendy, leading Volbragg to believe that Casper is setting him up.

The trio goes to the scientists' lab, where they reveal that Volbragg is getting energy from the electricity in the real world. Following this, Casper decides to use dampening dust, which Phineas gave him, to deal with Volbragg while Wendy uses the witch's wand to stop him, but he proves to be extremely powerful. Hot Stuff arrives and uses balloons as fake ghosts (which he used to trick the ogres) to distract Volbragg as he loses power, which gives Wendy the opportunity to use the wand against him. Volbragg turns out to have the power of being a hybrid of a ghost, a witch, and a devil, as Wendy has to say three phrases thrice to use the magic and take away his powers, causing the building they are in to collapse. Just as a large piece of debris is about to crush Wendy, Hot Stuff sacrifices himself by pushing her out of the way. With Volbragg dead, everyone in Spookytown mourns Hot Stuff's death, but his parents reveal that the only way to revive Hot Stuff is by putting him in a lava pit. When Hot Stuff comes out of the pit, everyone congratulates Casper and his friends, and they all throw a party to celebrate their victory.

• Casper – a young ghost who instead of scaring humans like all ghosts, wants to be friendly around them. He befriends Wendy and Hot Stuff as they team up to stop Volbragg.
• Wendy – a good-natured young witch who acknowledges the need to scare others, though she has her limits, and uses her magic to send humans back to their homes once they've been scared. She befriends Casper and Hot Stuff seeing that she can easily relate to them. With her magic spells, she uses them in an effort to stop Volbragg.
• Hot Stuff – a young devil who is the more trouble-making of the three, but when he befriends Casper and Wendy, he becomes nicer and more helpful when the others need him.

• Fatso, Fusso, and Lazo - Casper and Spooky's uncles and teachers who resent Casper’s nice attitude, and are willing to continue scaring humans to keep Volbragg imprisoned.
• Spooky - Casper's cousin who is the exact opposite in that he admires scaring humans.
• Wendy's aunts - Wendy's three aunts who admire scaring humans, but also try to keep Volbragg from escaping.
• Hot Stuff's family - a family of devils which consists of Hot Stuff's father, mother, and older brother.
• Professor Phineas Field - a human scientist who intends on collecting energy from other worlds, but accidentally causes a probe between Spookytown and the real world, including Volbragg's escape from prison.
• Eloise "Ellie" Essex - Professor Field's intern and lab assistant.

• Willem Georges Volbragg - the main antagonist of the miniseries. He is a tyrannical politician demon who was once human and wanted to take over New Amsterdam. When that fails, he seeks his intentions on Spookytown by collecting all the scares to become more powerful and feared. A mixture of three monsters, Volbragg was so powerful because he was part Devil, part Ghost, and part Warlock. but his scare collect was used as a prison in order to keep him contained. Some ghosts and witches managed to trap Volbragg in a scare-powered prison, therefore keeping Volbragg imprisoned as all races scare enough humans to keep the prison powered up. Volbragg created a sphere that could harness the energy generated by scaring humans in order to grow more powerful. The main trouble is partly caused by a human scientist, who discovers Spookytown and wishes to harness its power, but ends up freeing Volbragg this way.