Hole Monster

The Hole Monster is the alien creature from outside of the Pencilcosmos that is causing creation of the Hole, and inevitable destruction of the Pencilcosmos.

It is unknown what the Hole Monster is or its intentions. Most likely, it is just an extremely powerful creature that feeds off of different cosmoses to survive.

Bacterial
The main theory of the Hole Monster's origin is that it is simply an atom-sized bacteria to the verse above it. It feeds off of what it sees as subatomic particles, cosmoses. These cosmoses are the building blocks of the entire verse containing the Hole Monster, and none of the intelligent life forms care enough to intersect this specific atomic bacteria, when they might not even know atomic bacteria exist. Until something intersects the bacteria (or a way to penetrate its cellular walls is found), there is no escape out of it.