Question: Who is famous for saying "What's up, Doc?
Answer: Bugs Bunny
Bugs Bunny is a cartoon film character first pictured in 1938 as Bugs' Bunny. The present Bugs Bunny character has appeared in a series of animated films for Looney Tunes (which later became Warner Brothers) from the early 1940's through the 1990's.
Today he is the corporate mascot for Warner Brothers. He is usually depicted munching on a carrot.