Cujo is the central antagonist of the film of the same name.
Trivia[]
Reggie from Disney's Lady and the Tramp II: Scamps Adventure is based on Cujo because Reggie from Lady and the Tramp II: Scamps Adventure does have the same bad violent behavior as Cujo.
Cujo is one of the most tragic Steven King villains, one who was never a villain by choice, or does he actually enjoy it. The normal Cujo was a gentle giant, without a mean bone in his body. But when he was infected with rabies, the poor creature had lost his mind, and was not in full control of his actions. Killing him was actually a kindness as to end his suffering.