Donald Ragnvald Christensen (6 July 1916 – 18 October 2006) was an American animator, cartoonist, illustrator, writer and inventor. Christensen joined Warner Brothers' animation studio after the Disney animators' strike where he worked as a storyboard artist for Norman McCabe, Bob Clampett, and Frank Tashlin. After leaving Warner Bros. he worked independently for nearly four decades as a storyboard writer and artist for comic books and cartoon studios including Hanna-Barbera, Walter Lantz, and DePatie-Freleng.