An elder god, demon residing in its valley, it was the eternal rival of the Elder God of Earth Satha, most commonly known as Set, and sought to overthrow all the other Gods. He manipulated some of Set's worshipers into forming their own cult independent of Set, the Sect of the Red Serpent, and gave them the Serpent Scepter which canceled out the Serpent Crown's influence.
After killing Bragi and his tribe, Niord wanted to avenge his brother-in-arms, and used Satha's venom for his arrows to fight the demon. As he tried to get his attention a fur-covered being emerged playing a flute, but after killing the creature the flute kept playing and soon the Worm emerged. Niord tried to fight the demon by shooting it with his poisoned arrows, but the creature managed to throw the Aesir to the woods heavily injuring him, while the Worm retreated. As Niord was dying, the Worm sought to use his soul in his quest and reincarnated him through different millennia.
When Niord began dying as James Allison, the Wyrm used him and the bodies of his previous lifetimes to gather the warriors, Conan, Solomon Kane, Dark Agnes, and Moon Knight into a quest to defeat Set, which would allow the Wyrm to finally achieve his goal. However, after the defeat of Set, the heroes battled the Wyrm in the Hyborian Age, after learning the truth, and with their combined effort, along with the help of Allison, Khonshu, and Set's priestess, Satyne, managed to defeat the Wyrm.
- Immortality: as a demon, the Wyrm was nearly immortal.
- Resurrection: the Wyrm was able to reincarnate Niord through different millennia.
- Time Travel: the Wyrm was able to travel through different time periods.
- Mind Control: it was able to manipulate James Allison.
- The Worm was created by Robert E. Howard in his James Allison story "The Valley of the Worm", which was adapted in Supernatural Thrillers #3 (April, 1973), written by Roy Thomas and Gerry Conway, and penciled by Gil Kane.
- Though renamed "The Wyrm" in Conan: Serpent War, the Worm could be somewhat related to De Vermis Mysteriis, with Solomon Kane and Moon Knight finding forbidden books, among them seemingly De Vermis Mysteriis (the whole cover isn't seen on-panel), while attacking bases of worshipers of Set in .
- In his Cthulhu Mythos short story "Jerusalem's Lot (Night Shift; 1978), Stephen King introduced "The Worm", "Gyyagin vardar!' [...] Servant of Yogsoggoth, the Nameless One! The Worm from beyond Space! Star Eater! Blinder of Time! Verminis!", a being tied to De Vermis Mysteriis.
- In "Birthright!" (Monsters Unleashed #3; November, 1973), also written by Roy Thomas (without Gerry Conway) and penciled by Gil Kane, the Worm in the Lost Valley was possibly inspired by the Worm of the Valley of the Worm: He shares its name, resembles it in aspect, and the battle in which he dies is the stuff of later legends.
- 6 appearance(s) of Worm (Country of the Worm) (Earth-616)
- 1 mention(s) of Worm (Country of the Worm) (Earth-616)
- 3 image(s) of Worm (Country of the Worm) (Earth-616)
- 1 victim(s) killed by Worm (Country of the Worm) (Earth-616)