Blooper: Santa's sleigh is supposed to have eight reindeer pulling it (Dasher, Dancer, etc.), which would make 9 total when Rudolph is with them. But when we see the sleigh being pulled at the end, including Rudolph, there are only seven. The producers said they didn't have the budget to make eight reindeer.
Channel Hop: NBC held the broadcast rights to the special until 1972, when CBS snapped up the rights, and it has remained on the network since then. However, with the acquisition of DreamWorks Classics (the special's current rightsholder) by NBC's parent company, NBCUniversal, in 2016, the special could return to NBC once again when CBS's rights expire.
The title character was voiced by Billie Mae Richards, who was credited as Billy Richards from 1965 onward, as mentioned in obituaries mourning her death in September 2010. Kathleen Barr later played the character.
Averted in the Mexican Spanish dub of the 1964 special, where he was voiced by Jesús Barrero.
Keep Circulating the Tapes: The 1998 film and its sequel have been long out of print, both on VHS and DVD, with no plans for re-release for either. The sequel aired on ABC Family for a time until their rights lapsed in 2013. The fact that the films' producer, GoodTimes Entertainment, is bankrupt doesn't help matters.
Refitted for Sequel: Some time after Rankin/Bass replaced "We're a Couple of Misfits" with "Fame and Fortune", and before they put it back, they used "Misfits" in 1979's Rudolph and Frosty's Christmas in July, as a duet between Rudolph and Frosty the Snowman.
Yukon Cornelius was originally going to sing "Silver and Gold" instead of Burl Ives.
Word of God: Many wondered what made the doll a misfit. It was revealed decades later in a talk show when Arthur Rankin, Jr., said her problem was psychological, from feeling unloved. Jules Bass is quoted as saying "I dunno. Maybe she was an alcoholic or something?"