Isadore (Izzy) Klein 1897-1986 Was a Jewish- American Writer and Animator who had a Long Career in Writing and Animating. From 1916-1969. He also Served as a Member of the National Cartoonists Society
Isadore Klein was Born to a Jewish Family on October 18th, 1897. In Newark, New Jersey. He Studied at the National Academy of New York and Art Students Leauge, He first got his job as a Animator in 1916 and the Age of 19! He Later Worked at The Barre Studio for Mutt and Jeff Cartoons, But left to make Educational Films. When Sound Came in the Late 1920's He Returned to Cartoons. As He worked on Van Beuren, Walt Disney, Screen Gems, Hal Seeger Productions, and Famous Studios/Paramount Cartoon Studios.
Career at Terrytoons
Isadore Left Walt Disney in 1939. But his Carrer at Terrytoons was a Remarkable One, Why was it you ask? Well because he Was the one who Made Mighty Mouse along with Paul Terry And was a Writer for most of it's shorts. But his Career at the Studio was a Brief One. As He Left the Studio in 1944 after Writing Carmen's Veranda . 
Besides Working on Animation (And Retiring from the Medium Somewhere around 1969 After Writing Winky Dink And you) He also Worked on Newspapers and Magazines, And For Political Stuff. And TV Commericals
He Died In 1986, at the age of 87/88