Guardian

Guardians are creatures that can only found in the Depths.

About (Spoilers)
These entities are the protectors of the Depths region, barring what lies beyond from those who are not worthy. They look like tall black statues with multiple swaying arms carrying strings of beads. In place of a face, these creatures have an X inscribed in a circle (the symbol for the max karma level).

Each of these creatures exist entirely in the background of the screen, much like the legs of Rabbit walkers. Most Guardians are non-hostile, but the final two encountered in the Depths can attack the slugcat indirectly. Their behavior towards the slugcat depends on your current karma level. At karma level X, they will ignore the slugcat even if you walk past them. However, if you have any karma level below, their X symbols will glow red and they'll force you back to the entrance of the room. Repeat this three times and they will kill you.

Trivia

 * There is a video in which a player bypasses the guardians with what is considered to be an exploit with low karma level by consuming Mushrooms and throwing two Flashbangs. This video is currently the Any% world record for beating the game.