Mobile Offensive Underground Search Excavation and Retrieval Sentries

The Mousers are robots created by Dr. Baxter Stockman and through this affiliation enemies of the Turtles. The robots are about knee high. They have a head with sharp teeth and two legs. Their jaws are strong enough to bite through steel.

Description and abilities
Standard Mouser robots are of the approximate size and shape of a turkey. 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 with their gripping toes able to climb walls, and have a 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 Variations
There are also various other models of Mousers, but these are mostly prototypes or test models.
 * Mouser
 * Big Mouser (Teenage Mutant Ninja Turtles (1989 video game))
 * Mother Mouser (Teenage Mutant Ninja Turtles III: The Manhattan Project)
 * Giant Mouser (Teenage Mutant Ninja Turtles (2003 game), TMNT: Mutant Melee, Teenage Mutant Ninja Turtles: Battle for the City, Action Figure, IDW)
 * Prototype Mouser (Teenage Mutant Ninja Turtles (2003 game))
 * 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)
 * Scout/Swarm Mouser (Teenage Mutant Ninja Turtles (IDW))
 * Disposal Unit Mouser (Teenage Mutant Ninja Turtles (IDW))

History
The Mousers were first developed and designed by Baxter Stockman, ostensibly to combat the rat problem in New York. In reality, these robots were designed to enrich him by being used for criminal purposes.

When the Turtles and April O'Neil appeared on the scene, they rushed Stockman - and in the 1987 animated series the Shredder - the Mousers occasionally downright hordes on it. As combat units, however, Mousers are very limited especially by their dependence on a central control unit, which made ​​them vulnerable to appropriate sabotage tactics.

2012 series
A Mouser appears in the tie-in prequel comic, where Mikey trips over one. Mikey assumes it to be one of Donny's "toys".

A Robot Drone with a Mouser appearance appears in the episode I Think His Name is Baxter Stockman as part of an advanced combat suit that is separated by Leonardo's katanas and then develops a life of its own. Later Baxter Stockman builds his own version of the Mousers, with the same appearance and purpose as in the Mirage comics.

The Mousers officially appear in the episode Mousers Attack!. This time they behave more like their previous incarnations, burrowing underground to steal valuable items for their master. However, their name is now an acronym for "Mobile Offensive Underground Search Excavation and Retrieval Sentries", indicating that dealing with mice and rats was not their original purpose. Ironically, their vocals sound like cat meows. They attack their targets when said targets are sprayed. At first, Leonardo and Raphael had trouble with the Mousers. Fortunately, Donatello tells them that the spray wears off gradually and if someone got sprayed, it gives off a strong signal. As Baxter attempts to spray all 4 of them, he and Dogpound become the Mousers targets instead after Raphael slices the spray.

They appear again in Baxter's Gambit, summoned by the upgraded Stockman Pod to attack the Turtles, Dogpound, and Fishface.

In Booyaka-Showdown, Part 1, they appear with the brainwashed Kirby O'Neil when Karai captures April. This was the first time out of all of their appearances that they appeared without their creator, Baxter Stockman.

Their first appearance in the 2nd season is in Mikey Gets Shellacne, where they help Baxter Stockman fight the turtles.

Appearances

 * "I Think His Name is Baxter Stockman"
 * "Mousers Attack!"
 * "Baxter's Gambit"
 * "Showdown, Part 1"
 * "Mikey Gets Shellacne"