Only lasting one season with a total of 24 episodes the animated series Fonz and the Happy Days Gang was produced by Hannah-Barbera in 1980. The series ran for a total of two years from 1980 to 1982.
The series was based off the ABC series Happy Days and many of the actors from the real show lent their voices for the animated series as well. Several new characters were added to the show as well.
From what I see the show was created in response to the mass popularity of the television series Happy Days. Sadly as stated above it only lasted one series but left a great impression on retro cartoons, this is one everyone has to see.