H.R. Pufnstuf
Originally a mascot for a fair, H.R. Pufnstuf was a big deal for television viewers of 1969, when he appeared on NBC in a seventeen episode series fetauring a plot about battles between good and evil. The character was so popular that his shortlived show remained a regular fixture on Saturday mornings on NBC until 1973. Reruns on other networks have continued periodically ever since, despite the fact that the show is absolutely terrifying.