Space Emperor is the third episode of Uncle Grandpa Season 1, and the third overall episode of the series.
After Uncle Grandpa mistakes a kid for a real space emperor and sends him to a different dimension, he must rescue him and bring him back to where belongs.
The episode starts off with Melvin playing space emperor with his friends Nathan and Nameless Boy with Red Shirt. Melvin begins to demand things from his friends, despite them pointing out that the game he set up is unfair. Nathan and the boy with the red shirt get fed up with Melvin playing the game unfairly, so they decide to leave. As they are leaving, The UG RV crashes into the backyard they are playing in and sends the two boys flying into a tree. The two fed up friends stare in awe as Uncle Grandpa gives himself a crazy entrance. He greets them all with a "Good Morning". His greeting is cut short when he accidentally bumps into Melvin, who in turn begins screaming about how he is an intruder within the game they are playing. Unfortunately for Melvin, Uncle Grandpa takes him seriously and actually thinks he's a space emperor. Uncle Grandpa has Belly Bag give him a teleportation gun that shoots Melvin into a different dimension.
Thinking that he has done good by sending a space emperor back to his own dimension, Uncle Grandpa is about to take off. Before he is able to leave, however, Melvin's Babysitter comes out and calls for Melvin to come inside and eat a dinner sandwich she had prepared for him. When she finds out Melvin is gone, she becomes a bit distressed and decides to ask Uncle Grandpa for help. Now seeing the error he had just made, he decides to go on a rescue mission to save Melvin. Rather than tell the babysitter what happened, he abruptly leaves her with a bunch of questions left unanswered.
Uncle Grandpa goes through the portal he sent Melvin through and is immediately caught by guards who happen to be the Space Guards. Uncle Grandpa does not realize they are taking him hostage and begins to ask them questions about the whereabouts of Melvin. The guards order him to be quiet and tell him that they are going to take him to see Gornak. They travel to a strange and large golden castle where they end up throwing Uncle Grandpa into a large pit. Oblivious to what is about to happen, Uncle Grandpa calls out for Melvin in hopes that he will find the lost child. As he calls out, the guards let Gornak out of his cage. Gornak comes out angrily and ready to fight. Uncle Grandpa is oblivious to this anger and greets him with his usual "Good Morning". After the alien beast roars loudly in his face, Uncle Grandpa realizes that this is Gornak. However, rather than cower in fear, he is actually rather happy to meet the alien beast. Gornak crushes him with his fist in response. Uncle Grandpa emerges from his fist to tell him that he does not have time to play and needs to find Melvin soon.
Gornak kicked Uncle Grandpa in response. Uncle Grandpa then creates a doppelganger of himself and explains the situation to the doppelganger. The doppelganger offers to speak to Gornak for him to try and help the alien beast understand that Uncle Grandpa does not have time to "play". Gornak begins to beat up on Belly Bag as Uncle Grandpa explains to him that he cannot play with him right now. When that doesn't work, Uncle Grandpa creates another doppelganger to just simply walk away from the alien beast. This angers Gornak, so in response Gornak dives his elbow onto Uncle Grandpa. Uncle Grandpa appears in his mouth this time and reminds Gornak about his dental health. Gornak does not like this, so he chomps down on Uncle Grandpa. Uncle Grandpa then appears behind the alien beast, putting a saddle on his back and jumping on top of it. Uncle Grandpa begins to spank Gornak as he sternly tells him that he didn't want to have to do that to the alien beast. Gornak cries out in pain. The guards are impressed with Uncle Grandpa, thinking of him as a warrior. After Uncle Grandpa is done spanking Gornak, he lifts Gornak up and throws him back to where his confinement was, letting the door slam down on the creature's neck.
The guards pick up Uncle Grandpa and proclaim that he should be shown to "the emperor". Once inside the castle, the guards drop off Uncle Grandpa in front of the emperor's throne and inform the emperor that Uncle Grandpa is the "warrior that bested Gornak". The emperor turns around in his chair and reveals himself to be none other than Melvin himself. Uncle Grandpa is happy to have found him and encourages him to go home with him. Melvin refuses and tells Uncle Grandpa that his name is actually Emperor Zorth and he is getting the recognition and service he deserves in this dimension. Uncle Grandpa ponders about what he is going to do next. When he comes to a conclusion within his mind, he runs out of the room, telling Melvin that he will be right back. Shortly after Uncle Grandpa leaves, a strange man who looks similar to Uncle Grandpa enters the room. Melvin thinks he is Uncle Grandpa trying to trick him, so he orders him to take the costume off. The man informs him that he is not Uncle Grandpa, but Emperor Krell. He explains that he was previously on vacation and is unhappy to see someone else sitting on his throne. The henchmen also seem to confuse Emperor Krell with Uncle Grandpa as they are serving Melvin. This sparks an argument between Melvin and Krell. After going back and forth, Emperor Krell uses his powers to command Melvin to make him a dinner sandwich. At first, Melvin refuses. However, he ends up finding himself obeying Krell's command as he makes a sandwich for him. Emperor Krell then orders him to shoot fire out of his mouth. Melvin expresses how absurd he thinks that sounds before actually doing it. Melvin is shocked and afraid at this point, but tries to order Emperor Krell to stop mind controlling him. Emperor Krell ignores his commands and pleading, making him into a Pognog creature instead.
This finally breaks Melvin's demanding facade as he cries about how sorry he was to boss people around and how he would like to go home. Uncle Grandpa seems satisfied with that answer and comes back in to rescue Melvin. Emperor Krell steps down from his thrown ready to fight Uncle Grandpa, but Uncle Grandpa shoots a button that activates a trap door that Emperor Krell was standing on. Uncle Grandpa then turns Melvin back to normal. Melvin hugs him as Uncle Grandpa opens a portal to go back to their home dimension. Once there, Melvin's Babysitter hugs and thanks Uncle Grandpa for getting Melvin back home. Melvin's Babysitter waves Melvin inside the house and tells him that she will make him a dinner sandwich. Melvin instead offers to make her a dinner sandwich and holds up his butter knife hand which was never converted back from when he was a Pognog.
- The Gornak is a similar creature to Jabba's Rancor from Star Wars.
- The Emperor Krell's outfit may be a homage to Flash Gordon's antagonist Emperor Ming.
- Giant Realistic Flying Tiger, Pizza Steve and Mr. Gus are all absent in this episode.