Dagoth is a member of the second class of demons, who may be fallen or degenerate gods, but date from far later generations. At some point, under unknown circumstances, he became a servant of the extra-dimensional demon Shuma-Gorath.
In centuries or millennia past, Dagoth was worshipped as high priest in the city of Kalumesh. The citizens of that city served his every need and performed many bloody sacrifices in his name. Eventually the city was buried beneath the sea by monstrous waves which rose upward and smote the evil city. Dagoth himself was overwhelmed and buried as the city collapsed on him. All who worshipped Dagoth died beneath the smothering waves. The city came to rest at the ocean floor, outside what would be Cornwall, England.
Dagoth apparently escaped the confines of the city of Kalumesh at some point, and was rumored to have inhabited the depths of the waters outside Penmallow, Cornwall.
Henry Gordon inherited the manor of Witch House and read of the legends of Dagoth. He somehow attracted the attention of Dagoth, who apparently entered the manor and left the Starstone to be found outside of the nearby Tower of Dagoth. This stimulated Gordon's interest, and he and the house's caretaker, Blondine, used scuba gear to investigate and locate the sunken city of Kalumesh.
However, they also found Dagoth, who attacked the two. Fortunately, the sorcerer Dr. Strange was flying overhead (on a mission to locate evidence of Shuma-Gorath at Stonehenge) at the time, sensed Dagoth's power, and flew beneath the waves to save them. Strange created of an illusion of himself, which Dagoth attacked and seemingly strangled, but then found himself bound by the Rings of Raggadorr as Strange escaped with Gordon and Blondine.
That night, Dagoth summoned Blondine to activate the Starstone, which sent the people of Penmallow into a trance. Under Dagoth's control, they attempted to enter the city of Kalumesh to become sacrifices to Shuma-Gorath. This involved their walking into the sea, where they would drown beneath its waves in the journey. However, Dr. Strange again sensed the activities and Dagoth, and opposed him, freeing the people from their trance, so they could swim to safety at the surface. Dagoth attacked Strange, who gathered the ambient magic and used it to banish Dagoth to some unnamed dimension, never to return.
Dagoth, also referred to as the Dreaming God, was a deity worshipped by the people of Shadizar, particularly Queen Taramis. Centuries before mankind, Dagoth participated in a large battle with other gods, during which his source of power, a jeweled horn, was broken off. Dagoth fell to Earth in a weakened state and his body turned into stone, becoming a statue of a handsome human male with a hole in his forehead.
Somehow, the statue was acquired by Taramis. It was kept in the main anteroom of the palace where Taramis' followers could worship it. At other times, the Queen insisted on keeping it in her private quarters where she could be alone with it. She would often make love to it, or bathe it in the blood of her virgin handmaidens.
As written in the ancient Scrolls of Skelos, if Dagoth's horn were found and replaced in the forehead of the statue, it would bring about the evil god's resurrection, and as long as a virgin girl was sacrificed at the hour of the god's rebirth, everything would be fine. At least, this is what Taramis and her vizier, Xantares, assumed. They believed that if they completed the sacrifice, Dagoth would be under their control. The virgin chosen for the ritual was Taramis' own niece Jehnna.
Jehnna, induced into obedience by drinking drugged wined, placed the horn into the Dagoth's forehead. The statue began to move. An enraptured Taramis ordered Xantares to kill her niece. The ritual was interrupted by Conan's companions. Zula killed Xantares with her spear before he could slit Jehnna's throat. Immediately, the statue began to transform from a handsome man into a hideous, and very organic, horned beast as the Scrolls of Skelos feared.
Taramis was horrified as her "beautiful" god arose as a gigantic, reptilian beast. She attempted to kill Jehnna herself. Conan, who until now had been busy battling Bombaata, appeared and shoved Taramis toward Dagoth and he impaled her on his horn. Conan and his companions battled the resurrected god. He called down lightning to try and destroy the palace, and shrugged off both Zula's spear, Malak's throwing knives, and the swords of Conan and one of Taramis' guards. Dagoth killed the guard by stepping on his head, crushing it.
Akiro, watching from nearby, yelled to Conan that Dagoth's horn was his life, and in tearing the horn from the god's forehead, severely weakened Dagoth. As his life's blood poured from where the horn had been torn out, Dagoth collapsed, and was finally slain with a stab from Conan's sword.
It is unknown if Dagoth's monster form was his true form, or if he simply turned into that because of the ritual being interrupted. In any event, as a statue he was a handsome, helmeted man in a sarong with an ornate helmet. He had a hole in his forehead where the horn was meant to go, and was posed in a reclined position of serene relaxation, smiling benignly.
As a monster, he was several feet taller than even Conan, and the ornately jeweled horn become more natural in appearance, resembling an elephant tusk or rhinoceros horn. He had eyes on the sides of his head, and his mouth opened sideways and was filled with sharp teeth. He had enormous webbed hands and feet and fins on his arms and legs, and a long, lizardlike tail. Most bizarrely, his throat appeared to be open, displaying various organs and innards.
The true extent of Dagoth's power isn't known. What abilities he did display, however, included superhuman strength and endurance, and the ability to cause storms and call down lightning. He was capable of being injured, as evidenced by the numerous bloody slashes he received from the attacks upon him, but as long as he had the horn in his forehead, these wounds did not bother him in the least. With the horn torn free, Dagoth became so weak he could hardly even crawl, and could easily be killed.