Kathulos is the name of one or many entities (see notes):
- Kathulos was either a Great or a Lesser Old One,
- Kulthas of the Green Planet, or Kathulos of the Eternal Lives, was a demon of unknown origin and a living planet.
- Kulthas was an evil deity of the Pre-Cataclysmic Age.
- Kathulos the Slave-Seer was an unidentified being, and presumably the author of the Book of Kathulos.
During the Hyborian Age, the sorcerer Ranephi possessed a scroll or a tome from Kathulos the Slave-Seer (among other tomes of eldritch knowledge), whom he destroyed to prevent it from falling into peasants' or barbarians' hands.
Kathulos worked for Shuma Gorath and was granted power to draw Doctor Strange across the galaxy to its surface. Kathulos appeared to Strange in a giant plant and attacked and bound him with vines. He drew Strange into the Astral Plane to absorb his powers, but here Strange learned how to defeat him. Strange broke free and used the Crimson Crystals of Cyttorak at his root system and killed him. Leaving a barren rock, Strange traveled to the planets core, destroying everything.
- Kathulos was first mentioned by Robert E. Howard in "Skull-Face" (October-December, 1929).
- Kulthas was created by Robert E. Howard in "The Curse of the Golden Skull" (published in 1967).
- There is various mention to "Kathulos", who could be the same entity or not:
- The demons' entry of Marvel Zombies: The Book of Angels, Demons & Various Monstrosities #1 (September, 2007) (slightly updated in Official Handbook of the Marvel Universe A-Z #3; July, 2008) mentions Kathulos, an Old One, and Kathulos the living planet an a demon of unknown origin.
- The Appendix to the Handbook of the Marvel Universe makes various comments on Kathulos:
- The Kathulos' page mentions Robert E. Howard and H.P. Lovecraft's uses of the name, and distinguish it from the yet-to-appears Skull-Face from Howard's eponymous story.
- On Thulsa Doom's page, at the disambiguation section for Kuthulos, are listed separately "Kathulos, the planet-like demon", "Kathulos, aka Skull-Face", and "Kathulos the Slave Seer".
- Kattan-Tu's page and the masterlist of the Appendix distinguish "Kathulos the Slave-Seer" from "Kathulos" the planet/planetoid.
- The Book of Kathulos' entry in Tomes of Eldritch Knowledge mentions that "the god-demon Kathulos the Slave-Seer" has an uncertain relation to "the Old One Kathulos, an agent of Shuma-Gorath".
- Similarly, Kulthas has been mentioned, but could refer to different beings:
- In the adaptation of Robert E. Howard's story "Dig Me No Grave" (February, 1937), written by Roy Thomas and published in Journey into Mystery (Vol. 2) #1 (October, 1972), Kathulos' and Yog-Sothoth's names were replaced by Shuma-Gorath's.
- The demons' entry in Official Handbook of the Marvel Universe A-Z #3 (July, 2008) introduced the distinction between the Great Old Ones and the Lesser Old Ones ("powerful servants and spawn of the Great Old Ones"), but didn't specified Kathulos' classifcation. The Lovecraft & the Cthulhu Mythos in the Marvel Universe, at the Marvel Appendix, classifies Kathulos as a Lesser Old One.
- 3 appearance(s) of Kathulos (Earth-616)
- 3 minor appearance(s) of Kathulos (Earth-616)
- 5 mention(s) of Kathulos (Earth-616)
- 1 image(s) of Kathulos (Earth-616)