The Zippertile is a NPC found in the Number World. It is located in the southeast corner of the Numbers world, to the right of the door with 0's and 1's in front of it.
Overview
At first, it is similar to the other zipper wall decorations in Number World, however with an unhappy expression. Their appearance is determined by random chance. If it's in the normal state, the player is advised to wake up and return until it changes.
Zippertile is one of the few NPCs that you have to use the Knife on to access a new area, in most cases the Cat is enough to move a character.
When using the Knife on it, Zippertile opens its zipper to reveal a red-rimmed hole that gives entry to the The Stairway, where KyuuKyuu-kun can be found. Their mouth now smiles again and oozes a red liquid that borders the entry hole.
Entering the hole reveals that part of them can still be seen from the other side, however with some slight changes. The left eye is now round, not square and they seem to possess a small pink nose.
It does not react to any other Effects, however as it screams when the Knife effect is used, it is considered "alive" and not just a wall decoration.
