Unique knowledge that one, and only one, person in a group knows.
Mirla had a knowflake at pub quiz last night, being the only one of her team who could recall that "Major Tom" was performed by Peter Schilling.
An evil reindeer (possibly also a vampire), often determined to ruin Christmas.
Popularized in the more holiday-friendly reindeer-themed version of the party game, "Mafia"
Only after watching Blitzen trample the night watch-elf and cut the brakes on Santa's sleigh did Rudolph realize he was a renegaindeer.