Cujo is one of the more deliberately charged pet names in the registry — 72 records, rank 1,475, male-leaning, and every single one of those owners knows exactly what they're referencing. Stephen King's 1981 novel about a rabid St. Bernard is the entire context. Naming your dog Cujo is a statement about your sense of humor and your relationship with horror culture.
The King Reference
The 1983 film adaptation of Cujo cemented the name in American cultural memory as the definitive menacing dog name. Owners who name their dogs Cujo are almost always playing a deliberate irony — the dog is probably a big softie. A fluffy, gentle Saint Bernard named Cujo is a joke that lands perfectly; a genuinely aggressive dog with the same name would just be in poor taste, and most responsible owners understand the distinction.
Irony as Naming Strategy
The ironic pet name has a specific logic: you take a charged or threatening cultural reference and attach it to an animal who embodies the opposite energy. Cujo works on a dog who greets strangers with enthusiasm and falls asleep on visitors. The name becomes a constant low-key punchline that owners clearly enjoy. Compare Killer or Demon for similar ironic register at different points in the registry.
One Practical Note
Dog parks and vet offices will react to "Cujo" differently than to "Buddy." Most people will laugh; some might flinch before they realize the dog is wagging. It's a name that requires brief social management — which is either a feature or a bug depending on how much you enjoy the bit.