An Abyssal guardian is a monster that dwells in the Abyss, and also in the Abyssal Area (Fairy Ring code: ALR). Abyssal guardians can hit fairly high for their level, though they have low defence and are fairly inaccurate. Abyssal guardians attack with magic and are weak to arrows.
If hunting Abyssal monsters for their rune pouch drops, it is recommended to kill Abyssal walkers instead, which are slightly lower-levelled.
Abyssal guardians' heads have different sides, each representing a happy, angry, sad, and dead face. When it is idling, its happy face is at the front; when it is attacking, it will turn its angry face to the front; when it is being attacked, it will turn its sad face to the front; and when its health is reduced to zero, it will turn its dead face to the front before it dies.
Its head may be a reference to Pyramid Head from the game and movie Silent Hill.