Thulsa Doom is the main antagonist of the 1982 film Conan The Barbarian. He is a very powerful and ruthless undead sorcerer and Conan's arch-nemesis being the one responsible for the murder of his parents. He first appeared in the Kull short story "Delcardes' Cat" by Robert E. Howard and has since appeared in comic books and film as the nemesis of Kull, and later, one of Howard's other creations, Conan the Barbarian.
He is portrayed by James Earl Jones who also voiced Darth Vader.
Conan The Barbarian
This Thulsa Doom is considerably different from the literary one, who is described as having a skull-like face. Pre-production drawings showed this version of Thulsa Doom with the skull-like face, but as filmed, he is essentially the classic Conan villain Thoth-Amon, servant of the serpent-god Set. As such, he appears as an ordinary human in the film, though one said to have lived for a thousand years and with the power to transform into an enormous snake.
This Thulsa Doom/Thoth-Amon hybrid appears to have been re-imagined as a cult leader in the manner of the real life demagogues that had popped up in the decade previous to the film's release like Charles Manson or Jim Jones. In the movie he is shown to have an extraordinary command of his followers. For example, in one scene, after Thulsa Doom commands one of his female followers on a high ledge to come to him, she jumps off the ledge to her death. In this he resembled Hassan-i Sabbah, the Nizari leader, who according to Arab sources had one of his followers leap to his death to demonstrate his power to visiting dignitaries. Additionally Sabbah's hashassans would leave daggers on the pillows of dignitaries to intimidate them as did the cult in the Conan film.
He appeared when he and his legions invade the lands of Cimmerians for the first time, leading to a massacre of the people there including the young Conan's parents (the father was killed by Doom's dogs while the mother was decapitated by Doom with the father's sword). As the young Conan became a gladiator after years of slavery, Conan swore to avenge his people's tragedy by killing Doom.
Upon getting a mission from the old king Osric (whose daughter was kidnapped by Doom), Conan disguises himself as a priest to infiltrate into Doom's Temple of Set, but he's caught, tortured, and crucified on the Tree of Woe. Fortunately for Conan, he was rescued by a female brigand named Valeria and an archer named Subotai, who all agree to help Conan rescue the princess.
Upon infiltrating the temple again, Conan and his trio manage to rescue the princess and deliver her out from the temple, but Doom kills Valeria by using a stiffened snake as an arrow to fatally strike her in the waist. The next day, Doom sends his men to go after Conan, but Conan, along with the help from Subotai and the good wizard Akiro, manages to defeat Doom's forces, forcing Doom to flee back to his temple.
At the night following his men's death, Doom start to address his cult followers in his temples, but he's interrupted by the arrival of Conan himself. Rather than killing him, Doom instead tries to mesmerize him, but Conan resists and instead uses his father's lost sword to finally behead Doom, thus avenging the deaths of Valeria, Conan's parents, and the Cimmerians. Following Doom's death, all of the followers are freed of Doom's control and they return to their homes, right before Conan burns the temple. Then, he returns the princess back to King Osric afterwards before heading to his next adventure with his new friends.