tisTree's Holiday Comics! contains examples of:
- Christmas Elves: Holly and Ivy are elves who work for Santa Claus.
- Easter Egg: tisTree episodes have many Easter eggs, especially the Easter Special.
- Immortality: Multiple characters in tisTree are immortal, and immortality is a main focus of Trick or tisTree: A Spooky Musical Odyssey.
- The '90s: Yahoo! provides 90s technology liberally throughout the comics.