Thurl Arthur Ravenscroft (/ˈθɜrl ˈreɪvənzkrɒft/; February 6, 1914 – May 22, 2005) was an American voice actor and basso profundo known as the booming voice behind Tony the Tiger's "They're grrreat!" in Kellogg's Frosted Flakes television commercials for more than five decades. Ravenscroft was also known, albeit uncredited, as the vocalist for the song "You're a Mean One, Mr. Grinch" from the classic Christmas television special, Dr. Seuss' How the Grinch Stole Christmas!.
Ravenscroft did some voice-over work and singing for Disney in both the films and the attractions at Disneyland (which were later featured at Walt Disney World). The most well known of these attractions are The Haunted Mansion, Country Bear Jamboree, The Mark Twain Riverboat, Pirates of the Caribbean and Walt Disney's Enchanted Tiki Room. His voice acting career began in 1940 and lasted until his death in 2005 at age 91.