Ah! It Was Pete's Dragon!

Plot Summary for

Pete's Dragon (1977)

In New England in the early 20th century, Pete is a nine-year-old orphan escaping from his brutal adoptive parents, the Gogans, with his only friend, a cartoon dragon named Elliott. Pete and Elliott successfully escape to Passamaquoddy, Maine, and live with Nora, a lighthouse keeper, and her father, Lampie. Elliott is sought for medicinal purposes by the corrupt Doctor Terminus.

Medicinal purposes? Guess he wasn't purple after all.