The Munsters
Two of the original Munsters - Grandpa and Herman - were appearing together in a television show, Car 54, when they were approached to work on a new idea. The pilot was released in 1963, partly filmed on the old set of Psycho, and was a huge hit. Whilst originally made to look quite frightening, the characters' image became subsequently less threatening.
Despite their popularity with audiences, The Munsters lasted only two years, axed when Batman was introduced on the same time slot on another channel. Re-runs turned it into a classic.