Their origin is very similar to the comics: they first appear in the first episode Things Change, nearly killing Splinter and destroying the Turtles' lair, though they were able to destroy all the Mousers. In the next episode, they learned that the Mousers were created by Baxter Stockman to control the rat problem. Donatello gathered the remains of one Mouser and was able to fix it, but upon being fixed it immediately left the lair and eventually joined up with hundreds of others in the sewer. The Turtles engaged in an all-out brawl with the Mousers, discovering that this new batch was more durable than the last as a shot from a Shuriken barely damaged one. Eventually Leonardo discovered the only way to beat them is chop off their heads off, and the Turtles managed to destroy all but one; Donatello tries to capture it to study, but Raphael destroys it before he can.
Meanwhile, April O'Neil discovered Baxter was using them to rob banks and jewelry shops; as a result, Baxter sent four Mousers to kill her, but she was rescued by the Turtles. She later accompanied the Turtles to Stocktronics and encountered Stockman, who attempted to kill them with the Mousers. However, April and Donatello managed to get the Mousers to overload, destroying them and the building.
Mousers continued to make appearances throughout the rest of the series, including as aids to Stockman after he became a full-time member of Shredder's "staff." Later, Dr. Chaplin created a new variety of Mousers with four legs and the ability to transform into large spheres, which were deployed against the Turtles to retrieve a Triceraton anti-gravity generator from Hong Kong.
In the episode Head of State, Agent Bishop and Baxter Stockman create Organic Mousers to protect earth from aliens. Many years later Baxter used them to try to kill then-President Bishop. The Organic Mousers perished in a cave-in at Stockman's lab. After Bishop saved his life he told Stockman that the Department of Agriculture was interested in his Mousers.
Description and abilities
Standard Mouser robots are of the approximate size and shape of a turkey. They have a single eye and two enormous, hardened steel toothed jaws that can bite through concrete, brick and steel with ease. In addition, the Mousers are able to use their gripping toes to climb walls, and have a hollow body cavity, with which they can transport swallowed material or objects.
Standard Mousers only have a low intelligence and no independent thinking skills; they are basically drones and usually controlled by a central computer station or simply a remote control.
- Mouser v2.0 (Teenage Mutant Ninja Turtles (2003 TV series), Teenage Mutant Ninja Turtles 3: Mutant Nightmare)
- "Bishop's Mouser" (Teenage Mutant Ninja Turtles 3: Mutant Nightmare)
- Organic Mouser/Bio Mouser (Teenage Mutant Ninja Turtles: Fast Forward)