Answer: rattlesnakes

AnswerCrossword Clue
rattlesnakesRATTLESNAKE, any of several American pit vipers that have horny interlocking joints at the end of the tail which make a sharp rattling sound when shaken
rattlesnakesA heavy-bodied American pit viper with a series of horny rings on the tail that, when vibrated, produce a characteristic rattling sound as a warning