Thurl Ravenscroft, who provided the rumbling "They're Grrrrreeeat!" for Kellogg's Tony the Tiger ads and voiced many Disney characters, has died of prostate cancer, reports CNN. He was 91.

"I'm the only man in the world that has made a career with one word: Grrrrreeeat!" Ravenscroft told the ORANGE COUNTY REGISTER in 1996. "When Kellogg's brought up the idea of the tiger, they sent me a caricature of Tony to see if I could create something for them. After messing around for some time I came up with the 'Grrrrreeeat!' roar, and that's how it's been since then."

For Disney, Ravenscroft provides voices for many of Disneyland's rides, including the Pirates of the Caribbean, Splash Mountain, the Enchanted Tiki Room and the Haunted Mansion. For Disney films, he can be heard in CINDERELLA, THE JUNGLE BOOK, MARY POPPINS, ALICE IN WONDERLAND, LADY AND THE TRAMP and many others.

Born in Norfolk, Nebraska, Ravenscroft migrated to California in 1933 to study art. Soon after he was appearing regularly on radio, and by the late-1930s he was singing backup for Bing Crosby. After serving in World War II, he returned to Hollywood, where he sang with the Mellomen, a group that performed with Frank Sinatra, Danny Kaye, Rosemary Clooney and Elvis Presley.

In 1952, Ravenscroft's voice appeared in the first Frosted Flakes commercial.

Ravenscroft is survived by two children and four grandchildren.