- New Bot Day! It’s a Mouser! M.O.U.S.E.R.S. are Mobile Offensive Underground Search Excavation and Retrieval Sentries created by evil scientist Dr. Baxter Stockman, who used them to rob banks and do all kinds of other mischief. Cute and lethal! First appeared in Teenage Mutant Ninja Turtles #2 in 1984 and in many other TMNT media since then. Got it at Frank & Son’s Collectible Show yesterday. Keep fighting evil everybody!