In the original broadcast of 'Rudolph', Santa didn't return to the Island of Misfit Toys, to fulfil his promise to King Moonracer. Viewers complained so vehemently, that a new scene was produced with Santa and Rudolph returning to the Island for future broadcasts.
Paul Soles, who provided the voice of Hermie the Elf in the 1964 'Rudolph the Red Nosed Reindeer' Christmas special, also provided the voice for Spider-man in the 60s animated series.