Longcat is a white cat that floats around on a small cloud, repeatedly extending it's body to extraordinary lengths. Longcat is invincible to everything but T-rexes, Behemoths, and Dragons, because they will eat him, unlike his evil twin, Tacgnol, which is like any other enemy. Longcat will attack anything that attacks it. He is the only character in the game with unlimited HP besides Priest and other religous people. Unlike most Characters, Longcat and Tacgnol can't have ropes and other rope-like objects attached to them due to them having no rope points.
Both Longcat and Tacgnol are references to popular internet memes which involve pictures of very long cats.
It can be killed by Death. However, after it's touched, the Longcat will take a while to die.
Oddly, an immovable longcat will not move and cannot die. It will just stay there and not disappear, showing emotions.