Religion: Zoroastrian deity
Publisher(s): Gnome Press
First Appearance: Weird Tales (vol. 26) #6 (Dec. 1935): "The Hour of the Dragon"
First Appearance (Additional Details): (prose) Weird Tales (vol. 26) #6 (Dec. 1935): "The Hour of the Dragon"; (Marvel) "The Hour of the Dragon" in Giant-Size Conan #1 (Sep. 1974)
Creators: Robert E. Howard
Number of Appearances: 11
Comic Book Appearances: 10
Prose/Text Book/Story Appearances: 1
The mystic deity Ahriman has been referred to in many comics, particularly in Conan stories. An example set in modern times was in Marvel Two-In-One #49. In that story, Ahriman is the god worshipped by the villainous necromancer Ennis Tremellyn. Perhaps there can legitimately be said to be two (or more) powerful mystic deities named Ahriman, or perhaps they are all the same being. The extent to which the Ahriman portrayed in comics matches up in any way to the Ahriman of real-life Zoroastrian theology is debatable. In Zoroastrianism, Ahriman does indeed represent evil, so the fact that comics refer to an evil god Ahriman is not incidental.
Another question that can be asked is: Should the followers of Ahriman in comics be classified as Zoroastrians? In most regards, they do not seem like Zoroastrians. Moreover, contemporary Zoroastrians worship Ahura-Mazda (their name for the God, the supreme being of the universe) and regard Ahriman as a devil, the evil one. So any worshipper of Ahriman would actually be regarded as an apostate Zoroastrian, in a sense.
Ennis Tremellyn worshipped the god Ahriman and apparently derived some legitimate power from this being as well. Presumably the fact that he worships Ahriman (a Zoroastrian deity) means that Ennis Tremellyn is himself Zoroastrian. But further investigation into this story is warranted to determine whether Zoroastrian themes actually play a part in the story, or whether perhaps Ahriman name was simply borrowed and used as the name of Ennis Tremellyn's deity without any attempt to allude to the Ahriman of real-life Zoroastrian belief.
Suggested links for further research about this character and the character's religious affiliation: