Baxter Stockman is one of the Ninja Turtles’ recurring villains, appearing across many versions of the franchise since the early comics. His appearance and origin change between shows and comics, but the central idea remains familiar: a brilliant, dangerous scientist who becomes an enemy of the Turtles.
His abilities depend on the version. As a human, Stockman has formidable knowledge of science, engineering, genetics, and technology. He can create genetically altered life, robots, and advanced machines capable of acting on his orders. As a mutant fly, he keeps his intelligence while gaining greater physical abilities, wings, and the ability to climb walls. Some portrayals also give him acidic saliva capable of dissolving metal.
Stockman first appeared in Mirage Studios’ comics. There, he is a 36-year-old Black scientist, a genius with little regard for other people. He initially has no connection to Shredder and pursues his own criminal goals. His best-known inventions, the small robots called Mousers, are supposedly intended to solve New York’s rat problem. In reality, he uses them to tunnel into bank vaults. His assistant is April O’Neil.
April grows suspicious and confronts him. Stockman admits that he is using the Mousers to rob banks and plans to destroy city landmarks, partly because he finds it entertaining. He then tries to kill April, but the Turtles save her. April and the brothers later infiltrate his laboratory, shut down the Mousers, and bring his scheme to an end. The police arrest him.
The classic animated series gives Stockman a very different appearance: he is now a white, blond scientist. He initially tries to sell his Mousers honestly to Ajax Pest Control, but the company rejects him and throws him out. Shredder learns about the robots and hires him without explaining that he plans to use them against Splinter and the Turtles. The brothers defeat the Mousers and discover Stockman’s involvement.
After a battle with the Foot Clan, the Turtles question Stockman, who is later arrested. Donatello then “borrows” his van and equipment, using them as the basis for the Turtle Van and Turtle Blimp.
Stockman becomes a mutant fly in the second-season episode “Enter the Fly.” Sent to Dimension X to be killed, he survives an ordeal in which his body is merged with a fly. He initially attacks both the Turtles and Shredder, but Shredder persuades him to blame the brothers for his transformation. The mutation recalls the 1986 film The Fly, starring Jeff Goldblum, whose scientist character accidentally merges with a fly while using a teleporter.
Archie Comics initially follows the classic cartoon’s origin for Stockman. His story diverges during the Eye of Sarnath arc, a storyline I plan to cover in a separate video.
IDW gave Stockman a dedicated Micro-Series issue. General Krang holds him on Burnow Island, supervising construction of the Technodrome, a colossal machine intended to help Krang’s forces conquer Earth. Stockman has plans of his own, however, and secretly delays the project.
He creates a powerful, intelligent hybrid called Flyborg that can make its own decisions. When Flyborg attacks Krang’s soldiers, Stockman uses the distraction to enter a control room, access sensitive information, and discover a way to control the Technodrome. A closing flashback shows him playing chess with his father, who doubted his intelligence but taught him the value of making the right moves to win. We also learn how Stockman maneuvered to take over his father’s company, StockGen. The original issue was offered with two covers.
In IDW’s ongoing series, Krang supplies Stockman with resources to develop mutagen for creating super soldiers. Its psychotropic component increases intelligence, while the project also involves biological armor inspired by turtle shells. The special mutagen is stolen and lost. To obtain the psychotropic component, Stockman sends Old Hob and his Mousers after Splinter.
The 2003 animated series draws on Stockman’s Mirage origin. His failures come with increasingly brutal consequences. After losing to the Turtles, Hun brings him before Shredder, and Stockman is left missing an eye as punishment.
He does not become a fly in that series. Instead, he passes through different mechanical bodies, including an exosuit and a giant robot. After the giant robot is destroyed, his surviving remains are supported by a spiderlike robotic body.
In one alternate-future storyline, Stockman’s brain is attached to Hun’s wheelchair-bound body.
The 2012 animated series returns to the mutant-fly idea. Stockman eventually becomes human again when Michelangelo cures him with retro-mutagen.
Unlike the accidental transformation in the classic cartoon, Shredder deliberately causes this mutation. He activates the mutagen collar placed on Stockman to keep him from betraying the Foot Clan. A fly resting on Stockman’s body at that moment determines his mutant form.
Rise of the Teenage Mutant Ninja Turtles reimagines him as Baxter Stockboy, a child scientist obsessed with social media.
In the films, Stockman appears in Teenage Mutant Ninja Turtles: Out of the Shadows, connected to Bebop and Rocksteady’s mutation in his laboratory. His mutant-fly form also appears in the animated Batman vs. Teenage Mutant Ninja Turtles.
In Batman vs. Teenage Mutant Ninja Turtles, he is tasked with building a mutagen-dispersal machine for Ra’s al Ghul at Ace Chemicals, the famous Gotham City factory associated with the Joker’s transformation.
Stockman also turns up frequently in TMNT video games. Rather than attempt a complete list, consider the mobile game TMNT: Mutant Madness as one example. There, he is among the early playable characters unlocked during the opening missions.