Thurl Arthur Ravenscroft (1914-2005) was an American singer and actor who is best known for voicing Tony the Tiger, the mascot for Kellogg's Frosted Flakes. He was also the bass singer for the singing group, the Mellomen, which he also co-founded. He was involved with several Disney and Dr. Seuss productions.
He is also known for singing You're a Mean One, Mr. Grinch!. His name was accidentally left out of the credits, which led some to believe that the narrator and voice of the Grinch, Boris Karloff, sang the song, until Dr. Seuss cleared up the mistake. In The Cat in the Hat (1971 cartoon), he voiced Thing One.