One of the fastest adopted pieces of Santa lore in the 20th century was the reindeer Rudolph. Immortalized in song, Rudolph was born with a shiny red nose that caused him to be shunned by his peers. However, on a foggy Christmas Eve, Santa realizes Rudolph's nose could help his sleigh get through. After helping Santa complete his annual run, Rudolph is now loved by the other reindeer.
While the story seems quaint, in the 21st century, we begin to pick up on some problems. Rudolph is discriminated against for something he can't control. As he was born this way, comparing his plight to differing ethnicity or sexual orientation is almost obvious. It gets problematic in that Rudolph is appreciated for his differences only when they're useful to others. If Rudolph had been picked on for a red nose that didn't glow, he'd have no relief.
Rudolph's story first appeared as a book by Robert L. May in 1939 for Montgomery Ward. It was adapted five years later for animation by Max Fleischer. (It was later reissued with the song added to it.) A major difference from later versions is that it is not Santa's deer that belittle Rudolph. Rudolph lives in a town of reindeer that is completely separate from Santa's home.
The famous song adaptation would follow ten years later, made famous by Gene Autry. The song quickly became the famous version and many adaptations of the story since go off of that, leading in new directions.
One of the more famous and even more problematic versions is by Rankin-Bass, who have Rudolph as the son of Donner. Where it gets troublesome is that not only is Rudolph rejected by his peers, but also Santa Claus himself, who is especially grouchy in this incarnation. This causes Donner to force Rudolph to hide his nose so he can have self-respect. For LGBT people who might identify with Rudolph, this can really hit close to home.
Rudolph eventually runs away from the North Pole, joined by an elf who wants to be a dentist, an out of luck prospector, and an island of "misfit" toys. Rudolph and his friends manage to save his mother and his love interest Clarice, while managing to tame a snow monster before a blizzard hits, forcing Santa to use Rudolph's nose to guide the sleigh.
The problem is that while Rudolph's peers eventually realize that they shouldn't have been unkind, it takes Rudolph accomplishing feats to do this. Santa winds up being the worst because he doesn't appreciate Rudolph until the very end when he needs his help. Reindeer or people shouldn't be shunned for their differences regardless of whether or not these differences are useful, but this lesson is never pointed out.
To wrap it up, here's a fun cover of the song featuring Judy Garland and Bing Crosby.