Baxter Stockman (IDW)

Baxter Stockman is the owner of Stock Gen Laboratories, a genetic research lab. On the payroll of the mysterious General Krang, he has his scientists researching applications of a Mutagen for Krang's warriors, most of which involves animal testing and harvesting.

Some of the experiments involved increasing the intelligence of rats, and adapting Turtle plastrons as natural armor. Ninja had broken into the lab and scared Stock Gen's intern, April O'Neil, in an attempt to steal the Mutagen and some of the animals. As a result, during their escape, the Turtles and rat were exposed to the Mutagen, as well as an alley cat.

Krang charged Stockman with retrieving the Mutagen from the rat Splinter's bloodstream. Baxter had recruited the mutated cat, Old Hob, to send his Mousers after Splinter, and although he was successful in capturing Splinter, he was then claimed by the Foot Ninja clan. Stockman instead extracted the Mutagen from Old Hob's DNA, and finding no more use for the feline, shot him dead.