Abner Jenkins, also known as the Beetle, MACH-1, MACH-2, MACH-3, MACH-IV, MACH-V, MACH-VII and MACH-X, is a character appearing in American comic books published by Marvel Comics. Created by writer Stan Lee and artist Carl Burgos, he debuted in Strange Tales #123 (August 1964) as the original Beetle, a supervillain wearing an armor plated, mechanical suit he had designed himself after growing frustrated with his ordinary job as an aircraft mechanic and deciding to turn to crime. Although in his first appearance he fought the Human Torch and the Thing of the Fantastic Four, later storylines established Jenkins as a recurring foe of Spider-Man, usually working as a henchman for various criminal organizations opposing the hero. Jenkins later formed his own criminal organization known as the Sinister Syndicate.

After abandoning his Beetle persona, Jenkins was recruited into the Thunderbolts—a supervillain team assembled by Helmut Zemo to pose as superheroes to gain access to the technology of the Fantastic Four and the Avengers, groups which had both seemingly perished while fighting Onslaught. Jenkins became known as "MACH-1", using a modified version of his Beetle armor that was designed for faster flight and higher altitude. The Thunderbolts were introduced in Incredible Hulk #449 (January 1997), and although they originally went along with Zemo's plan, later storylines depicted them as disobeying him due to enjoying the attention and adulation they received as heroes. Seeking redemption, Jenkins was convinced to give himself over to authorities to serve out an outstanding prison sentence in exchange for the Thunderbolts being granted immunity. During his time in jail, Jenkins helped the authorities out, which led to him working for the government after his release from prison. He later began working at the Raft prison as head of security and re-joined the Thunderbolts, now a team of reformed criminals trying to earn time off their sentence by working for the government.

The character has been adapted from the comics into several other forms of media, such as animated television series and video games.

Abner Jenkins first appeared as the original incarnation of the Beetle in Strange Tales #123 (August 1964), and was created by Stan Lee and Carl Burgos. As MACH-1, he later joined the supervillain team, the Thunderbolts, who were masquerading as superheroes to conceal their true goals, in The Incredible Hulk (vol. 2) #449 (January 1997). In subsequent storylines, all members of the team, including Jenkins, became disillusioned with their leader, Baron Helmut Zemo, and decided to reform and become heroes. After some time away from the team, Jenkins appeared as a regular character in Thunderbolts since issue #144, and has appeared as a supporting character since the title transitioned into the Dark Avengers beginning with issue #175. During his time with the Thunderbolts, Jenkins made numerous upgrades to his armor, resulting in various iterations, from MACH-2 all the way to MACH-X.

Born in Baltimore, Maryland, Abner Jenkins was a master mechanic at an aircraft parts factory who became dissatisfied with his boring, low paying job. Using his considerable mechanical knowledge, Jenkins built an armor-plated, strength-augmenting suit, a pair of wings, suction-fingered gloves, and a cybernetic control helmet. Calling himself the "Beetle", Jenkins decided to use his battle-suit for fame, wealth, and adventure, becoming an enemy of Spider-Man. He later joins Egghead's Masters of Evil and founds the Sinister Syndicate, a team of mercenaries.

When most of Earth's heroes, including the Avengers and Fantastic Four, are seemingly killed battling Onslaught, Helmut Zemo recruits Jenkins and a number of other villains to posing as a superhero team called the Thunderbolts. Jenkins adopted the guise of "MACH-1". However, the Thunderbolts' members begin to enjoy heroism and convert the group into a legitimate team.

When the Thunderbolts uncover and thwart a Commission on Superhuman Activities (CSA) conspiracy to exterminate superhumans, Hawkeye blackmails the CSA into pardoning the Thunderbolts in exchange for the group's silence. CSA agent Henry Peter Gyrich insists that he will not go along with the deal unless Hawkeye is imprisoned for his vigilante activities. Hawkeye agrees despite the protests of his teammates and surrenders to federal custody.

Most of the rest of the Thunderbolts, including MACH-2 and Songbird, are pardoned and released. However, they are forbidden from public use of superhuman powers or costumed identities. MACH-2 and Songbird turn their equipment over to authorities and move to Burton Canyon, Colorado, where Abner Jenkins finds work as a tech support specialist.