Takamoto died Monday of heart failure at Cedars-Sinai Medical Center, Warner Bros. spokesman Gary Miereanu said.

In a career that spanned more than six decades, Takamoto assisted in the designs of some of the biggest animated features and television shows for Disney and the Hanna-Barbera animation team. They included Cinderella, Peter Pan, Lady and the Tramp,101 Dalmatians, The Jetsons and The Flintstones.

But it was his creation of Scooby-Doo, the cowardly dog with an adventurous heart, that captivated audiences and endured for generations.

Takamoto said he created Scooby-Doo after talking with a Great Dane breeder and named him after Frank Sinatra's final phrase in Strangers in the Night.

The breeder "showed me some pictures and talked about the important points of a Great Dane, like a straight back, straight legs, small chin and such," Takamoto said in a recent talk at Cartoon Network Studios.

"I decided to go the opposite and gave him a hump back, bowed legs, big chin and such. Even his color is wrong."

Takamoto also created other famous cartoon dogs such as Astro from The Jetsons and Muttley, the mixed-breed that appeared in several Hanna-Barbera animations. He also directed the 1973 feature Charlotte's Web.

Takamoto was survived by his wife, Barbara, son Michael and stepdaughter Leslie.

Funeral arrangements were pending.