The Iron-Bound Book of Skelos (sometimes presented as the Iron-Bound Books of Skelos) contained the most fearsome magic-lore on Earth, secrets from wizards already old in the early days of Atlantis.
During the Hyborian Age, only a few copies of the Book of Skelos were known to exist, all closely guarded.
- All those were allegedly complete, save for one, Thoth-Amon's, from which a page was stolen and ended up in the Temple of a Thousand Gods of Messantia, Argos.
- Tosya Zul possessed one page of the Book of Skelos, which was the only magical writing he took with him in his fleeing of Zamboula.
- Shu-Onoru possessed the iron-bound book of Skelos, which was one of the tomes his slave Zula read to gain magical knowledge.
- Ranephi possessed it, among other tomes of eldritch knowledge, but burned them as his end drew near, to prevent this knowledge to fall in the hands of peasants and barbarians.
- According to Thoth-Amon, another incomplete, (or nigh-complete according to Karanthes) copy was present in Kheshatta, City of Magicians, one complete existed within the Aquilonian Librarium.
- According to Thoth-Amon, another copy was in a secret temple in Vendhya.
- One complete, reptile-bound, copy existed on the Nameless Isle, in the Western Sea, on a an altar to Tsathoggua the Toad-God, and was brought by Zarono and Menkara to Thoth-Amon, who was much disliked by the present, as the altar stored the Cobra Crown, a far more valuable artifact.
- Another wizard named Karanthes, high priest of Azoth, either possessed a copy of the Book of Skelos, or somehow accessed to its content relative to Azoth.
- The Book of Skelos was created by Robert E. Howard in "The Pool of the Black One", adapted in Savage Sword of Conan #22 and #23 (September and October, 1977) which does not feature or mention the Book of Skelos.[verification needed]
- The iron-bound Book of Skelos was stated to have been written by Vathelos the Blind, according to Robert L. Yaple in the part IV of his essay "The Gods of the Hyborian Age: Demi-Gods and Demons". If that apply to the Marvel Universe version of the book is unknown.
- The Sorcery and Demoncraft's entry in Handbook of the Conan Universe #1 and the listing of Tomes of Eldritch Knowledge on the Appendix stated that Vathelos had compiled the Book of Skelos.
- In The Forever Phial story from Savage Sword of Conan #8, both the book of Skelos and the book of Vathelos are shown to exist separately in the Marvel Universe.
- The Iron-Bound Books of Shuma-Gorath section of the "Tomes of Eldritch Knowledge" entry in Official Handbook of the Marvel Universe Mystic Arcana: The Book of Marvel Magic #1 states that "Shuma-Gorath, Skelos, Vathelos and others created books", hinting that Vathelos and Skelos (and their respective books) are indeed separate people and objects, with both authors having written his own book.
- The listing of Tomes of Eldritch Knowledge on the Appendix mentions an uncertain relationship between the Books of Vathelos and of Skelos.