Klytus, called General Klytus, is the commander of Ming the Merciless' secret police force in the Flash Gordon movie. As a computer view screen comes into view with a blue and green world in the center, his name is the first word of dialogue spoken in the movie by a bored Ming, who asks Klytus if he has a 'plaything' to offer him that day. Klytus tells him about an obscure body in the SK System that is known as "Earth" by its inhabitants. Ming remarks that it looks peaceful before using his Power Ring to select from a number of disasters on his natural disaster control panel. Klytus joins in amusement, enthusiastically asking Ming if he will destroy the Earth. Ming replies that he likes to play with things a while, before annihilation.
He is next heard, but again not seen, replying to one of the cyborg members of the Secret Police, as the minion reports a rocket ship entering their control range, parallel to star field Zigma 12. Klytus orders that the ship be brought through the Sea of Fire safely and landed.
Klytus is first seen in the Grand Audience Chamber of the Imperial Palace, standing on the dias where Ming soon makes his approach. Klytus is clothed in shimmering black robes, with a hood framing the gold, metallic mask of his face. His right arm is immobile, without a sleeve, and encased in gold. After Ming's subjects praise him with their customary chant: "Hail Ming, Hail! Ruler of the Universe! Hail Ming, Hail! Emperor of the Galaxy!" Klytus begins the tributes, starting with the Hawkmen of Sky City. As King Vultan of the Hawkmen raises the fabled Ice Jewels of Frigia as his tribute, he is interrupted by an angry Prince Barin of Arboria, who claims that the Ice Jewel is their tribute, not Vultan's and that the Hawkman stole it while they were burying their dead on Frigia. A fight is about to erupt, but Klytus shouts at them to put down their weapons and sternly reminds them that no one dies in the Imperial Palace without a command from Ming. Barin and Vultan appear to obey, but Vultan lunges again at Barin. Klytus demands that Vultan obey, or Vultan will have to sacrifice his daughter, a lovely pink winged girl who is also present among the Hawkmen. Vultan obeys and is silenced. The next subject to offer loyalty is Prince Thun, but after a confrontation with Ming in which Thun is killed, Ming hands Klytus a blood stained sword. Flash Gordon, present with Dale Arden and Dr. Hans Zarkov in the Audience Chamber, comments that Ming is a psycho. This comment is overheard and repeated loudly by Ming's deadly floating robot servant. Klytus demands to know who said it and Flash is brought before them, to which Klytus asks, "Who are you?" After the earthlings state their names, Klytus reminds Ming that their planet is the one he has been tormenting with natural disasters recently.
Ming takes a liking to Dale Arden and uses his Power Ring on her to caress her from afar and cause her to act in a sensual manner in front of everyone in the Audience Chamber. Klytus comments that Dale's reaction to the ring rivals that of Princess Aura, Ming's daughter. When Ming decides to keep Dale for himself, Klytus summons Ming's guards for her. Flash Gordon rebels against this and begins to battle, in traditional American football style, the guards. Ming observes this and summons Klytus over, asking if the guards are on the right pills and that maybe Klytus should execute their trainer. Klytus shouts for the guards to come to him, which they do. He tells the guards that Flash is playing some barbaric game and they should match him in formations. The guards set off, but are easily defeated by Flash and he is ordered to be publically executed.
Klytus visits Flash in the prison, where he remarks that Flash does not look well and observes that Flash refused his final meal, which will no doubt upset the Chef. After asking Flash if he has a final request, he anticipated that Flash would want to see Dale, so he has Ming's Concubine brought in. Flash, who has a spiked contraption covering his head, demands to "see" Dale. Klytus obliges him and zaps off the steel covering with a laser beam. He tells Flash and Dale they have 'until the sands run out' of an hourglass that flows in reverse. He leaves the prison chamber after calling the two of them pathetic.
Klytus is next seen leading the funeral procession to the gas chamber and bows to Ming before taking his place next to the doorway of the chamber. He does not say anything to Flash Gordon as the rebellious earthling is led into the chamber, even as Flash looks at him in contempt after refusing to be touched by the guards. When Flash is strapped into the chamber, Klytus signals the release of the gas with a black silken cloth, which he then uses to polish the mouth-piece of his golden mask.
Klytus is present when Ming mind-wipes Dr. Zarkov, commenting to the scientist that they are just 'emptying his mind.' As he watches the memory erasing procedure, he sees images of the earthling dictator Hitler, and remarks that he showed promise. At the conclusion of the mind wipe, he tells General Kala not to program Zarkov with anything above Level 3, because he doubts if the human mind could take it. He then has to leave the chamber, unaware that Kala orders Zarkov programmed at Level 6. He later observes Zarkov and appears to be pleased at the reprogramming.
After Dale Arden escapes Ming's bedchamber, Klytus orders Kala to activate agent Zarkov to intercept her, thinking to trick her. When he overhears that Flash Gordon is alive, Klytus, along with Kala, are stunned. He is suspicious to learn that Flash has been taken to Arboria for sanctuary. He allows Zarkov to leave the city with Dale in hopes of following them. An angry Ming comes to the Secret Police command center and Klytus tells him he has located Dale, who is with Zarkov. Klytus tells an enraged Ming that Flash Gordon is still alive. He has suspicions of who might be responsible, but says he will need Ming's authority to pursue things the way he wants to.
After Aura returns to Mingo City, she is captured and brought to the Torture Chamber, where she is whipped by Kala and interrogated by Klytus, who demands to know the truth. When Aura refuses, Klytus tells Kala to bring him the bore worms. Aura threatens to tell Ming what he has done to her, but Klytus reveals that Ming has been watching from behind a privacy screen and allows the torture to continue. After securing Aura's confession, Klytus asks if she is to be executed, but Ming says she will be banished to Frigia after his wedding to Dale Arden for a year and then married to a grateful Klytus. This offer is made on the condition that Klytus bring Flash and Barin to Ming, which Klytus says will be a pleasure.
Klytus is aboard his insectoid ship and is awakened from a respite by one of his officers who have spotted a Hawkman patrol 400 Mongo miles east bearing Gordon and Barin. Klytus returns to his nap after he is told it will take additional time to reach Sky City. He then goes to the city, alone and without guards, telling Zarkov he will be liquidated for treachery and threatens the destruction of Sky City to Vultan if he does not turn over the fugitives. Klytus then tells Barin he will be arrested. Barin comments to Klytus that he tortured Aura, but Klytus says he thinks she found it rather enjoyable. Barin punches Klytus in the gut and calls for Flash, who rushes at Klytus and hurls him onto the spiked battle platform of Sky City. Klytus attempts to reach out in defiance, but falls back onto the spikes and dies, his eyes and tongue bulging out in a gruesome manner.
His death signals the destruction of Sky City.