The snail waving to Finn is no more possessed by the Lich.
Lady Rainicorn is seen again, this time being pregnant.
The frisbee flight sequence at the end of this episode is a homage to the sleigh flight sequence in "Spot's Magical Christmas" (1995). Experienced voice actor Jim Cummings, who voices the Owl, Lenny the Beaver, and the Porcupine in this episode, also voiced the male reindeer in Spot's Christmas.
It has never been explained how Finn regained his normal size after being shrunk in this episode.
The lines "in the tree part of the tree" is a reference to the quote from Pirates of the Caribbean: Dead Man's Chest (2006) "part of the crew part of the ship".