Droopy (a.k.a. Droopy Dog or Droopy Poodle) is a cartoon character created by Tex Avery and voiced (initially) by Bill Thomson in a series of cartoon shorts for MGM. He first appeared in the short Dumb-Hounded in 1943.
Droopy is short, sag-cheeked, white-furred and redheaded, and always looks like he's half-asleep. He talks in a mellow drawl and rarely smiles. He was broadly based on Wallace Wimple of the "Fibber McGee and Molly Show", although today he's recognized as a cartoon icon all his own.
Droopy's 1957 short One Droopy Knight was even nominated for an Academy Award, although this short was directed by Michael Lah instead of Tex Avery. His last MGM short was in 1958, although he did appear again in a sort of cameo as an elevator operator in the movie Who Framed Roger Rabbit.