The main four use Portal Doors to play a variant of hide and seek.
"Let's Play Interdimensional Hide and Seek" contains the following tropes:
- Alternate Universe: The main four find one, the world of "Let's Learn" as opposed to their "Let's Play". Alternate Universe!Kaeloo's transformation takes place in reverse and is activated by cuddling rather than irritation, and her frog form is a strict teacher. Alternate Universe!Stumpy is intelligent, and Alternate Universe!Mr. Cat is a quiet, Literal-Minded idiot (as opposed to Stumpy who is an idiot and Mr. Cat who is a genius).
- Bizarro Universe: See Alternate Universe above.
- Downer Ending: The main four get stuck with Alternate Universe!Kaeloo, and Kaeloo is stuck in the other universe with no way to return home.
- Literal-Minded: Stumpy throws books at the Alternate Universe!Main four and yells "Eat books!" Alternate Universe!Mr. Cat, who is the opposite of Mr. Cat and therefore a total idiot, proceeds to pick up a few books and swallow them.
- Mirror Universe: See the entry for Alternate Universe above.
- Ostrich Head Hiding: Quack Quack does this when playing hide and seek, despite being a duck and not an ostrich. It works on Kaeloo, Alternate Universe!Stumpy and Alternate Universe!Quack Quack.
- Scooby-Dooby Doors: Kaeloo, Stumpy, and Quack Quack do this using Portal Doors. At one point, Stumpy's counterpart from an Alternate Universe also joins in.
- Stern Teacher: Kaeloo's counterpart is a strict teacher who yells at her "students" and insults them.
- Trapped in Another World: Happens to Kaeloo in the end, since Mr. Cat accidentally throws her through the Portal Door after mistaking her for her Alternate Universe counterpart and then smashes the door.
- Yank the Dog's Chain: Kaeloo, Stumpy and Quack Quack to go to the other dimension to check it out. Mr. Cat stays home. Just as he becomes happy to have finally gotten some time alone, the Bizarro Universe!main four, who are even more annoying than the normal main four, come to the regular universe and start bothering Mr. Cat.