Baxter Stockman created them to control the rat problem of New York city. However, Stockman was actually working for the Utrom, Shredder, and Ch'rell who used the robotic Mouser to rob banks of their money.
Stockman used his Mousers to attack the lair of the Teenage Mutant Ninja turtles and their Master Splinter. However they survived.
When Stockman's assistant April Jones, found out what his Mousers were really doing she tried to tell the authorites and he tried to kill her with his Mousers but the Turtles saved her and destroyed his Mouser factory.
The Shredder, furious of his failure had Stockman's left eye removed as punishment.
metallic bird like machines with steel jaws and a flashlight on top of the head.