If it's not obvious by now, I have a thing for anthropomorphic creatures; that is, creatures who are part man, part animal. Killer Croc, pictured below, is one of my favorites. One of Batman's arch-nemesis, Killer Croc is one of the few comic book villains who is truly scary. Aside from the incredible strength, speed, claws and toothy grimace, there was always the possibility that Killer Croc might actually eat you if you caught him at the wrong time.
A tragic figure as well, Killer Croc suffered through a life of abuse, rejection and ridicule, his mind slowly devolving to a more primal, bestial state. While not a major player in the Batman line-up, I'm never disappointed whenever Killer Croc is showcased. Oh, and venom or no venom, Croc can kick Bane's tights wearing arse any day.