Chubby bunny (variations include similar sounding chubby bunnies, fluffy bunny, yummy bunny, chubby monkey, and pudgy bunny) is a recreational game that involves the placement of an increasing number of marshmallows or similar items into one's own mouth and stating a phrase that is intended to be difficult to utter with a filled mouth. The phrase can be "chubby bunny" or its variants, but the suppressive structure is typically more important than which words are used. The game is often played where marshmallows are readily available, such as around a campfire.

In the game, each participant usually places a marshmallow into their mouth and says something similar to "Chubby Bunny". If they are able to state the whole phrase, usually in a comprehensible manner that the other participants wholly concur to, they pass that round. Each successful player then adds an additional marshmallow to the one already in his or her mouth and repeats the phrase. A player who fails to complete the phrase is eliminated from the game. The process continues until only one player remains. After the penultimate player loses the game, the winning player might have to place one more marshmallow into his or her mouth and may have to state the phrase once more. The winner of the game is the player who fits the most marshmallows into his or her mouth. Some variants of the game require the winner to actually ingest the marshmallows.