The first film to feature a character entirely created by computer was a Steven Spielberg production that did not go down in history.
Titled Young Sherlock Holmes , the film is directed by Barry Levinson, dates from 1985 and includes a sequence of approximately 30 seconds with an evil knight emerging from a stained glass window .
The character was created by the Lucasfilm Graphics Group (which would become Pixar a few years later) and took 6 months to complete.
Oddly enough, this sequence hasn’t aged badly. Because the character was cleverly designed, the result still looks decent today.