Almost certainly the most well-known evil clown (save for Batmans archnemesis, the Joker; more on him later), Pennywise is modeled after real-life serial killer John Wayne Gacy, aka Pogo the Clown, a.k.a. "The Clown Killer." Gacy was convicted of sexually assaulting and killing 33 boys in 1980; he posed as a clown ...