Guardian

Guardians are creatures that can only be 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 are currently 4 known exploits for bypassing guardians at any karma level, commonly used in speedruns. 1) Eating a mushroom and throwing two flashbangs to blind the guardians temporarily.  2) Manipulating the guardians to throw you straight up and then throw objects to reach the pipe.  3) Distract the guardians with another living creature, such as a grub or hazer.  4) Abuse load times to despawn the guardians.