First Appearance: Adventures into Fear #14 (March 1973).
Appearances: Adventures into Fear #14, 15, 19, Man-Thing v1 #1, 22, Giant-Size Man-Thing #3, Howard the Duck #22-23, Marvel Team-Up #68, Man-Thing v2 #11, Howard the Duck Magazine #1, and perhaps others.
Years Active: 18,000 B.C.E.-present.
20,000 years ago, before the fall of Atlantis, the sorceress Zhered-Na played the Cassandra and prophesied the destruction of the island kingdom. This led to her being cast out of Atlantis and forced to flee to an Atlantean colony in "Thuria," aka America. Once there a cult of Atlanteans formed around her.
The cult, and Zhered-Na herself, had various adventures until the Cataclysm which destroyed Atlantis. After that Zhered-Na's cult turned against her and murdered her. Before this happened, however, Zhered-Na (who could see into the future, after all) took the advice of the alien god Agamotto and rendered her best worshipper, Dakimh, immortal.
Dakimh, grateful for this, continued Zhered-Na's work over the next 20,000 years, fighting D'Spayre (the enemy of Zhered-Na) and helping to spread the Good Word Of Zhered-Na.
In the modern era Dakimh helped instruct Jennifer Kale, a powerful young sorceress. Presumably Dakimh had many other adventures across the span of his (very) long life, adventures which await telling.
Dakimh was a powerful enchanter.