If a cat has done horrible things in their life, or otherwise are not accepted into StarClan, they end up in the Dark Forest.

In the Dark Forest, prey will sometimes be heard somewhere in the undergrowth, but it is impossible to catch is as there is actually no prey at all. Cats in the Dark Forest are banished to walk alone for the rest of their existence, and will slowly begin to fade as they are forgotten by living cats.

The Dark Forest is a dark, shadowy forest with lots of tall, dank, dying trees. It is a dull, vast and empty place with cold, thick, foggy and damp air, and an echoing silence. The sky is black and starless, and you can hardly see past the tall trees that block out the sky. Mist wreathes around the thick, sticky, bare forest floor. There is a thick, mud like river with dark and lifeless water, with no stepping stones or fallen trees to cross it.