Donald Ragnvald Christensen (July 6, 1916 – October 18, 2006) was an American animator, cartoonist, illustrator, writer and inventor. He was sometimes credited as "Don Arr". Christensen was a graduate of the Minnesota School of Art in Minneapolis. After finishing school he worked for the Walt Disney Studio from 1937 to 1941. He left the studio after the 1941 Snow White production strike, during which he met his wife-to-be, Ivy-Carol Van Horn, a special effects detail artist. Christensen then worked briefly at Warner Bros. studio, primarily as a storyboard artist for Bob Clampett's animation unit. After leaving Warner Bros. he worked independently for nearly four decades as a storyboard writer and artist, primarily for Western Publishing, Dell and Gold Key comic books, as well as Hanna Barbera, Walter Lantz Productions, DePatie-Freleng Enterprises, and other cartoon studios. He wrote and provided illustrations for such comic book titles as Magnus, Robot Fighter, Donald Duck, and Uncle Scrooge. He was involved with the Southern California Comic Artist Professionals Society for many years, and was a past President of the Comic Art Professional Society (CAPS). Christensen died in Las Vegas, Nevada on October 18, 2006, at the age of 90 of natural causes. He beat the odds that he would not survive past 40, having been a Type I diabetic since the age of 13.