Qsheufs are creatures that are native to the Averentroverse. They resemble most whales except they have altered physical abilities and attributes. For starters, they are negative sized, at -22 Planck lengths long. They also have a diet of Antentroverses, unlike most traditional whales' diet of krill and other small sea creatures.
These creatures are someone's only way of escaping an Antentroverse.
There is approximately 150 of them inside the Averentroverse.