After a few months as an inbetweener at UPA in 1955, Erv Kaplan transferred to the background department, where he worked on several Magoo shorts. He also worked for Larry Harmon on the "Bozo The Clown" show, for Ed Graham on "Linus the Lionhearted", and (briefly) for Disney ... but that's not what he's best known for.
Erv was one of the very few people to have worked for Filmation from first day to last, a twenty-three-year stretch without a layoff. As head of the background department he worked on every cartoon show and feature they ever produced. He retired after Filmation's close, but came back a few years ago to do keys on a couple of episodes of "King Of The Hill".