Fluffy is Oscar the Grouch's pet elephant on Sesame Street. She lives inside of Oscar's trash can, & all that is ever revealed of her is a trunk waving out from the trash can (a similar device was later used for Elefancio on Plaza Sésamo). However, book illustrations have often shown Fluffy in her full glory.
Regardless of how much of Fluffy is on display, she is always very vocal, often trumpeting loudly. This was achieved using recordings of actual elephant trumpets.