- "There’s something odd and different about these “Irregular” episodes…"
- — Official Happy Tree Friends website
Irregular Happy Tree Friends episodes according to the show's official website. This playlist was phased out following the website's revamp in late 2014. Shorts included in this playlist are completely outside any other series or theme but are still tied to the show in a way (for example, Banjo Frenzy being the pilot short for the show). This playlist also used to be known as the Outside the Box playlist in the Atom website.