Bill Hanna-co-creator of cartoon megastars like Fred Flintstone and Yogi Bear-died March 22 at the age of 90. Hanna and longtime partner Joe Barbera first teamed up in 1937 at MGM on Tom & Jerry, but it was in television where Hanna-Barbera made its name, dominating the networks' Saturday mornings. Hanna is survived by his wife of 65 years, Violet; a son and daughter; seven grandchildren; Barbera; and dozens of animated characters.