By this time, Potterton had an excellent art portfolio, including a comic book; he was hired and spent the next two years there as an assistant animator.

During this time, Potterton also founded the Grasshopper Group, a cooperative with the mission to help London's animators produce their projects.

He met Norman McLaren, the Scottish animator who was already on his way to becoming the star filmmaker at the National Film Board of Canada (NFB).

In 1960, he was offered a job as a filmmaker at Lars Calonius Productions, one of the largest TV and commercial animation films in the USA.

[3] In 1967, Potterton's NFB colleague George Dunning asked him to work on his film Yellow Submarine, then being produced to feature The Beatles.

The company produced Peter Sander's The Selfish Giant and Larry Kent's Fleur Bleue (The Apprentice) in 1971,[4] as well as Mike Mills' The Happy Prince in 1974 and, in 1975, The Little Mermaid and The Christmas Messenger.

He directed live-action and animated sequences for The Electric Company and Sesame Street; for the latter, he created the character of 'George the Farmer', who appeared in 18 episodes.

[5] In 1981, Potterton was hired by producer Ivan Reitman to direct the animated feature Heavy Metal for Columbia Pictures.

In 1988, Potterton created and directed The Smoggies, a 53-episode animated series which aims to entertain and educate young children about environmental issues.