Cujo was a massive, male St. Bernard owned by the Camber Family. Cujo was once a friendly and playful companion, but when he got rabies from a bat bite, he went insane and was turned into a vicious killer that attacked anybody who came near him.
Cujo
During the events of the novel, Cujo was bitten by a bat and got rabies from it. For the next few days, he became very bloodthirsty and dangerous, eventually killing Gary Pervier and Joe Camber. When Donna Trenton and her son, Tad, go to the Camber's farm for an auto repair, they are attacked by Cujo and spend three days in their car hiding from him. By this time, Cujo is now completely covered in sweat, blood, grime, froth and mucus, and the smallest things could set him off. When the phone rings, Cujo flies into a rage and viciously attacks the car, breaking a window in the process. Cujo bites Donna in the leg when she tries to escape and get help, and she barely survives the merciless and destructive attack. Luckily, the sheriff arrives, only to be savagely mutilated by Cujo after a brief struggle.
Meanwhile, Tad is dying of severe dehydration and Donna decides that she has to do something or else her son will die. She makes a daring escape from the car and Cujo attacks. Luckily, Donna is able to grab a discarded baseball bat from a junk pile and fend the dog off. She beats the dog with the blunt instrument, but the breaks when it strikes Cujo's face. Cujo lunges, and she falls backwards. However, when the dog jumps on her, she jams the broken end into Cujo's stomach, impaling him. Donna is traumatized and throws the apparently dead dog off of her and uses the sheriff's revolver to break her son out of the car. She takes him inside and gives him water. As he starts to revive, a barely alive Cujo uses the last ounce of his strength to jump through a window. The mortally wounded Cujo lunges, but Donna manages to retrieve the sherriff's revolver from the counter and shoot him in the head, killing him.
In the book, Cujo's death is much more graphic. The end showdown is the same, but when Donna breaks the bat, she impales him in the eye with the sharp broken end, killing him instantly.
Other Appearances
Along with the posessed automobile Christine he makes a cameo appearence in "Cat's Eye" where he chases the titular cat General. He kills with multiple bite and scratch wounds.
In an episode of Will & Grace, Karen mentions Cujo's name when Will's dog begins licking the drops of her martini
