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.