What has four frogs but doesn't have a croak?

The answer to the riddle "What has four frogs but doesn't have a croak?" is a set of playing cards, specifically a deck of cards that includes the four kings, often depicted as frogs in some playful interpretations. The term "croak" refers to the sound frogs make, which playing cards obviously do not produce. Thus, while the cards may represent frogs, they remain silent.