Takamoto who suffeerd a heart attack was VP of special projects for Warner Bros. Animation until his death. Most recently, Takamoto storyboarded the 2005 Tom and Jerry animation short The Karateguard, and was instrumental in the design of many characters in the current Cartoon Network and Kids’ WB! animated series Krypto the Superdog in the US. He also served as a consultant on Warner Bros. Animation’s ongoing Scooby-Doo direct-to-video series, including the 2006 release Scooby-Doo! Pirates Ahoy! and the upcoming Chill Out, Scooby-Doo.

Warner Bros. Animation president Sander Schwartz says, "Iwao Takamoto was not only a tremendously talented designer and artist, he was a beautiful human being. Iwao was always ready with a wide smile, a firm handshake and a warm welcome. Iwao’s designs will be his legacy for generations to come. Those of us who had the privilege of working closely with him will miss his mentoring presence, his good counsel and his unparalleled talent and spirit."

Disney hired him as an apprentice in-betweener in 1945 – just two months before the end of World War II.

Takamoto trained under Disney’s legendary 'nine old men' including Ollie Johnston, Marc Davis, Milt Kahl, Ward Kimball, Frank Thomas and Eric Lawson. While at Disney, Takamoto worked on short animated cartoons as well as full-length films, including Cinderella, Peter Pan and Lady and the Tramp.

In 1961, Takamoto moved to Hanna-Barbera Studios, where he helped reinvent cartoons for television. Virtually all the characters and cartoons released by Hanna-Barbera over the following four decades were touched by the design and artistry of Takamoto. As a character designer, it was his job to create the look and images of the characters based on an idea for a proposed cartoon show.

Takamoto designed Scooby-Doo, Shaggy and the rest of the Mystery Machine crew. He named the Great Dane after the late crooner Frank Sinatra’s Strangers in the Night rendition where, at the end, Sinatra sings "Scooby Dooby Doo." At a recent chat with Cartoon Network Studios personnel in Burbank, Takamoto offered some tidbits regarding his approach to creating the Scooby-Doo design.

He said, "There was a lady at (Hanna-Barbera) that bred Great Danes. She showed me some pictures and talked about the important points of a Great Dane, like a straight back, straight legs, small chin and such. I decided to go the opposite and gave him a hump back, bowed legs, big chin and such. Even his color is wrong."