In the 1987 cartoon, their main antagonists are a Japanese ninjutsu master, Shredder (Oroku Saki), an extraterrestrial called Krang, and two mutant punks, Bebop and Rocksteady, while in the 1984 Mirage comics, Shredder ends up killed by the turtles in the first issue. Krang's appearance is inspired by the Utroms, an extraterrestrial race in the Mirage. The Utroms, however, aren't villains.