Star Warners is the final episode of Pinky and the Brain. Despite this, most of the cast of Animaniacs play very prominent roles in this episode. The entire episode is a parody of the original Star Wars trilogy.
The episode starts with a recreation of the opening from A New Hope. The Goodfeathers, Major Nurse, and Ralph the Guard appear as Stormtroopers. After an invasion, Girth Plotz appears. Meanwhile, Dot Warner gives Brain-2-Me-2 a disc with the plans for Girth Plotz's ultimate weapon; the Mega Star. Girth Plotz spots her and she escapes, with the Stormtroopers hot on her trail. Brain-2-Me-2 escapes with Pinky-O and plans to use the weapon to take over the galaxy. 3-Pinky-O mistakes Brain-2 for a refrigerator, and while searching for his leftovers, Brain-2 accidentally activates the escape pod, launching them to planet Ratatouille.
Meanwhile, Girth Plotz has kidnapped Dot Warner and demands to know where the plans are. Dot insists she'll never tell, so the guards take her away. Dr. Otto Scratchansniff alters Plotz that the space pod has just escaped with Brain-2 and is heading towards Ratatouille. Plotz orders a search for "that fridge".
Brain-2 and Pinky-O are walking through the desert when they are encountered by Mindy, who mistakes him for a vaccum cleaner. Brain-2 tries to convince Mindy of his plans, without success. Finally, Mindy zaps the two robots with a magnet, paralyzing them. Wakk Slylicker drives up to Mindy and buys the two robots, thinking Brain-2 is a garbage can. Back at home, Wakk accidentally activates a message from Dot Warner begging Slappy Wanna Nappy for help. The three head off to get help from her. Slappy knows where she can get a pilot. Back at the ship, Girth Plotz tortures Dot with Pip Pumphandle.
Slappy, Brain-2, Pinky-O, and Wakk Slylicker arrive at the studio of Mos Eisner. Slappy's conversation with an alien is interrupted by Brain-2 and Pinky-O being slammed against the wall. It is then revealed that the "pilot" was, in fact, a pilot to a TV series named I Love Slappy. Just as Brain-2 bemoans that they needed a pilot who can fly, Yakk Soho and his co-pilot Chewbooboo break through the walls with their ship, the Bicentennial Lemon. The Stormtroopers soon track them down and they flee in the ship. Yakk Soho reveals that their ship is a pizza delivery ship.
Dot has had enough with Pip Pumphandle's conversations and breaks down, saying she'll tell Plotz anything. However, when asked about the plans, she coyly says "What plans?" Fed up, he points the Mega Star at Dot's home planet, the Comedy Planet, and screws up their TV reception so that Ken Burns' History of Paddleball is on every channel. Back at the Bicentennial Lemon, Slappy notices that Scooby-Doo has been preempted for Ken Burns' History of Paddleball. Wakk Slylicker notices that the Mega Star is behind the plot to suck the humor out of the universe. Slappy pulls him aside and tells him that he will need to learn comedy from Skippoda. Skippoda gives Slylicker a glowing mallet, which he accidentally pounds Brain-2 with, and teaches him how to make gookies. After that, they leave.
In the next act, the credits scroll reveals that Yakk Soho, Pinky-O, and Chewbooboo have been captured by Flabby the Butt, who is angry that they failed to deliver a pizza to him in 30 parsecs or less. He is about to kill them by tossing them into the Pit of Fear, but Yakk Soho offers him a hot pizza. Flabby accepts, and he opens the box to reveal that it held pizza guns. They fire the guards into the pit, and a goofy chuckle reveals that they succumbed to the clutches of Baloney. They fire more pizza at Flabby and rescue Minerva Mink.
The Bicentennial Lemon flies to the Mega Star. Brain-2 tells Pinky-O about his plans to rule the galaxy. Yakk Soho, Slappy, and Slylicker make their way inside the halls of the device. Slappy leaves to use the bathroom. Brain-2 and Pinky-O take a separate path, where they are noticed by Scratchansniff and Nurse, who get confused about what exactly Brain-2 is supposed to be. In the meantime, Soho and Skylicker break the walls to Dot's cell, only to be spotted by Scratchansniff, who chases them. Slappy exits the bathroom and runs into Girth Plotz. Slappy remembers that Plotz took her cartoons off the air, and they engage in a fight.
Brain-2 and Pinky-O make their way to the control room. In the meantime, Slappy and Plotz are still fighting, and he even manages to break her mallet. While she stalls, Plotz swings his mallet at her. The Warner siblings run into the area, and Skylicker is shocked at the presumed loss of his mentor. He pulls out his mallet and begins fighting with Plotz, breaking things along the way. Slappy is reading a magazine on the table which the two fight on. When Skylicker says "I thought you just died," Slappy says "Dying's easy. It's comedy that's hard." Brain-2 finally succeeds in making his transmission, but nobody is impressed. Plotz knocks Slylicker's mallet out of his hands. Wondering what to do, Skippoda comes to him in a vision telling him to "use the gookie" to fuse tense situations with humor. When Plotz finally corners Skylicker, he makes a gookie. Even though he thinks it's ridiculous, he breaks into laughter anyway. Brain-2 continues making his transmission, only for Skylicker to come on and make gookies while doing so. The robot tells him to go away, but the audience is highly amused by the silly faces. Not even Brain-2 can resist laughing. Everybody soon begins making gookies and bursting into laughter, even Skippoda. The Mega Star turns into Skylicker making a gookie.
The Warners, Slappy, Skippoda, the robots, and Chewbooboo each receive an award for their hard work. While Yakko and Wakko kiss Nurse, Pink-O and Brain-2 head to their home planet Acme to take over the galaxy.
- Outside of Mos Eisner, an Instant Martian makes an appearance.
- Inside of Mos Eisner, Gossamer, Eggbert, Daffy Duck, C.L.I.D.E., Baloney, K-9, and Mr. Skullhead can be seen. Marvin the Martian announces his plans to blow up the Earth to Minerva Mink.
- The Monstars, the alter-egos of the Nerdlucks from Space Jam, also made a cameo as patrons at the cantina bar.
- Pinky thinks Slappy Wanna Nappy will help him get a brain. The scene after shows the three skipping off to her house in a parody of The Wizard of Oz.
- While pitching her pilot, Slappy says her show "is like The Lucy Show, but with a squirrel." The Lucy Show is a sitcom starring Lucille Ball and was the follow-up to I Love Lucy.
- I Love Slappy is a reference to I Love Lucy, a 1950s sitcom starring Lucille Ball.
- Spacefeld is a parody of Seinfeld, a sitcom starring Jerry Seinfeld.
- The family on the Comedy Planet resembles the Jetsons.