Buttercup ranks #427 with 290 entries, registered female. The name belongs to the flower-and-yellow-things cluster of pet picks, named for the small bright yellow wildflower (genus Ranunculus). It functions as a permanent visual descriptor that happens to live on the license paperwork.
The Princess Bride and Powerpuff layers
Two pop-culture anchors keep Buttercup in active rotation. Buttercup the protagonist of The Princess Bride (1987) gave the name a romantic, slightly fairytale register. Buttercup the green Powerpuff Girl (1998-onward) added a tougher, more spirited read for younger owners. The two readings coexist because both characters share a kind of stubborn warmth.
Breed lean and color fit
Buttercup lands disproportionately on yellow, golden, or cream-coated breeds where the flower visual matches the pet directly — yellow Labs, Goldens, blonde Cocker Spaniels, and cream-coated mixed breeds. There is also a meaningful cluster of orange tabby cats, palomino-coated horses, and yellow-fronted small parrots wearing the name across species.
The serious-context limitation
Worth flagging: Buttercup is locked permanently in the cute-name register, and that limits how the name reads on a working dog or in any public context where the call lands sharply. A vet calling Buttercup in the waiting room is a different kind of moment than calling Atlas. Owners who pick it have decided that the soft register is the entire point. The human Buttercup page shows essentially zero SSA presence — this is a pet-side name.