The Omni-Omni is the last layer of the Nested Reality and contains everything that has the prefix "Omni".
Surprisingly, life does exist here; It comes in the form of Square beasts, Cube beasts, and Omni-Beasts. Square beasts Are the weakest of the beasts, only controlling 0.000096% of the Omni-Omni. The Cube beasts Can control 0.02% of the Omni-Omni, and Omni-Beasts control 13.8% of the Omni-Omni. The rest of the 86.2% of the Omni-Omni is controlled by a singular creature. However, the creature has never taken an Omni-Selfie, so we don't have any clues about it. They are rumored to be called The Omni-Omni-Omni, though.
There is nothing outside of the Omni-Omni as we know of yet, but some creatures HAVE tried to escape. For example, the Omni-Beasts created the first ever Omni Class Spaceship, meaning it can travel an entire Omni-Universe In one second. However, after 99,482,842,829 OYC's, the spaceship ran out of fuel. A few septillion Omni-Universes were traveled, and the lowest 17 layers of the Nested Reality were also exceeded.