Sheen's Brain
Sheen's Brain (Title Card)

Episode 11
Season 2
Airdate March 8, 2004
Invention Brain Gain Helmet
Previous Love Potion 976/J
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Sheen's Brain is the 11th. episode in season two of The Adventures of Jimmy Neutron: Boy Genius.


Sheen, due to his inability to focus, is about to fail a test that will prevent him from moving to the next grade with his friends. After Sheen fails a challenging history test, Jimmy and Carl try to tutor him, but Sheen won't listen to them. In a desperate attempt, Then Sheen begs Jimmy to turn the Brain Drain helmet into a Brain Gain helmet to make him a genius like him and Jimmy reluctantly agrees. Then the helmet works and then Sheen becomes a genius like Jimmy.

The next day, Sheen passes the math test, but then he acts rude, disrespectful, and arrogant to his friends, due to his increasing intelligence. Then he tricks Ms. Fowl into letting him play hooky, which it makes Jimmy and Carl very concerned. Then Sheen goes to the Candy Bar, where his head has grown to an enormous size and then he orders Sam to give him a free Sundae after correctly guessing the amount of jelly beans in a jar. Then Jimmy turns the helmet back into Brain Drain mode and then he tries to place it on Sheen's head, but Sheen has gained psychic powers and then he refuses to give them up, then he uses his new powers to torture Jimmy, Carl, Libby, and Cindy. Then Sheen decides to use his new powers to plunge Retroville into darkness and turn it into his empire. Then he declares himself as the town's evil and powerful dictator and then he makes Libby his queen (but only after bribing her with robes and jewelry). 

Then Jimmy and Carl go back to the lab and then they realize that Sheen's I.Q. will keep growing to infinity until his head explodes. Then they decide to trick him into putting it on by disguising the Brain Drain as a crown. However, Sheen figures out their plan, and then he decides to punish them by using his new reality-warping powers to torture them, despite Libby's protests. Then Jimmy and Carl try to warn Sheen about his head exploding, but he refuses to listen and then he continues to torture them. As his powers increase, Sheen abandons his position as an overlord and then he declares himself a god. Then Libby leaves him in a huff and then Sheen tries to go after her. 

In one final attempt to drain Sheen's brain, Carl and Jimmy disguise themselves as Ultra Lord to convince Sheen to change back and despite his new intelligence, Sheen's easily fooled. They then try to convince Sheen to put the helmet on, but Sheen refuses to take any orders from them, and then it causes him to brutally strike Jimmy and Carl with a lightning bolt. Sheen floats over to Jimmy and Carl and then he sees them lying on the ground, believing them to be dead. This causes a distraught Sheen to realize that his new powers have turned him into a monster, and finally he renounces his powers and intelligence. By putting the helmet back on his head, Sheen drains his own brain, restoring himself to normal and then the town turns back to normal. Then, Sheen realizes that Jimmy and Carl are alive and then he apologizes for what he did. Then Jimmy and Carl accept his apology, but this doesn't stop Sheen from getting his just comeuppance, as he starts getting painfully zapped by the Ultra Lord costume. 

The next day, after Sheen answers the chemical name of salt wrong, he shrugs it off, and despite passing the math test and not being in danger of being held back, he tells Jimmy and Carl that he's glad about not being a genius anymore. However, when his friends invite him over for TV watching, he declines and then he tells them that he has accepted a job offer for the money, which he promptly starts, albeit with plenty of spelling errors. 


  • "Ow! That hurt!" - Sheen
  • "Hey, look, TV!" - Sheen
  • ”TV go dark!” - Sheen
  • "Silence!" - Big Headed Sheen
  • "I told you, I used a complex algorithm based on the dimensions of the jar!" - Big Headed Sheen
  • "Uh-huh, yesterday you thought seashells were money! Today you’re using algorithms?" - Sam
  • "Don't come any closer, Neutron!" - Big Headed Sheen
  • "Hey, little big head! I've just cleaned there." - Sam
  • "My intelligence is wasting here! I shall be building empires, commanding armies! Today Retroville, tomorrow, THE WORLD!" - Big Headed Sheen
  • "Oh! Me first, me first! Was that a rhetorical question?" - Butch Pakovski
  • "I'm afraid of commitment!" - Ms. Fowl
  • "Big deal! My dad and I do the crossword puzzle all the time." - Cindy Vortex
  • "Attention, Retroville! I said...ATTENTION, RETROVILLE!!!" - Big Headed Sheen
  • "Sheen, there is no way i'm a- did you say robes and jewelry? What the heck, i'll give it a shot. (giggles)" - Libby Folfax
  • "(Carl sucks his thumb while cuddling a stuffed llama. He looks at Jimmy and Sheen and stops sucking his thumb and puts away his llama.) What?!" - Carl Wheezer
  • "That's not the point." - Jimmy Neutron
  • "Butch, Nick, grab him!" - Jimmy Neutron
  • "Libby Folfax, come on down!" - Big Headed Sheen
  • "Sheen, let them down!" - Libby Folfax
  • "No, that's gravity. We haven't gotten there yet." - Big Headed Sheen
  • "Hmm... It is rather fetching, just throw it on my head!" - Big Headed Sheen
  • "I control the wind, and I shall rain fire down the heavens! Good bye Sheen the overlord, hello Sheen the god!" - Big Headed Sheen
  • "That's it! I've had it with you, and your big freaky head!" - Libby Folfax
  • "Wait, come back! You'll like being the wife of a god! I'll let you choose the patio furniture." - Big Headed Sheen
  • "Wait a minute, how do I know your not an impostor?" - Big Headed Sheen
  • "Well, if you wanna make sure it's me, why not ask me a series of difficult trivia questions?" - Ultra Lord
  • "Hmm... Very resourceful, but let's see how quickly you think in, QUICKSAND!" - Big Headed Sheen
  • "So Libby, what decor were you thinking up for our castle?" - Big Headed Sheen

Carl: (reading) "Tom has three pieces of bubble gum." (Cut to Sheen, pointing one finger at a time and counts on each one; he continues o.s.) "If he trades all his gum to Ida for two raisins per piece..." (Back to him.) "How many raisins will Tom have?"
Sheen: What sort of idiot would trade bubble gum for raisins?
Jimmy: That's not the point.
Sheen: What is he, some kind of health nut?! If ya ask me, Tom needs counseling. And what kind of name is "Ida"? What's it short for: "I'd have preferred a different name"?!
Jimmy: Sheen, concentrate!
Sheen: I am concentrating. (pointing o.s.) Hey, look, TV.

(The dark haired procrastinator runs out of frame, and we hear a power up sound. Cut to him, seen from behind the TV as the Ultra Lord theme plays, and the TV suddenly turns off one second later.)

Sheen: TV go dark!

(Cut to Jimmy, having used the remote.)
Jimmy: Carl, let's go to Plan B.
Carl: (giving a thumbs up) Right, Jimmy.

(Pan quickly to Carl having placed something on Sheen; the latter is now covered in various spherical metal plates, five on his shirt, three on his head.)

Sheen: What's this?
Jimmy: Negative Reinforcement. Every time you get distracted, Carl will issue a small shock to your thorax.
Sheen: Sounds like fun!

  • "Oh, is that all, and what if we all went around freakishly enlarging our friends' heads!? HUH!?" - Cindy
  • "I don't understand it, I was only trying to boost his IQ so he'd pass the math test!" - Jimmy
  • "Wow, he'll be really good at board games." - Carl
  • "No Carl, you don't understand. Sheen's brain is programmed to keep growing. If we don't get that Brain Drain Helmet on him soon, his head will explode." - Jimmy Neutron
  • "Baby lamas in the meadow, baby lamas in the meadow. Oh no, one of them is escaping! He's heading towards town... town rhymes with crown! JIMMY AND I DISGUISED THE BRAIN DRAIN HELMET AS A CROWN!!!" - Carl Wheezer
  • "Sheen please we’re trying to help you! Your brain is growing at a dangerously fast pace!" - Jimmy
  • "Where were you born?" - Big Headed Sheen
  • "Good. What's your favorite Mid-Morning snack?" - Big Headed Sheen
  • "Correct. What did Robo-Fiend say when you blasted him with your ION Ray?" - Big Headed Sheen
  • "That's right! He said Ow! Yah!, you are Ultra Lord! Join me Ultra Lord, with my brains and your magma canon, well rule the universe!" - Big Headed Sheen
  • "I need you to, drain your brain." - Ultra Lord
  • "HUH, but why?" - Big Headed Sheen
  • "Your too smart. The other super powerful guys will think you’re annoying." - Ultra Lord
  • "I won't do it!" - Big Headed Sheen
  • "Your hero Ultra Lord commands you." - Ultra Lord
  • "Good bye brain, old friend." - Big Headed Sheen
  • "Don't worry Sheen. At least acing the math test means you won't be left back." - Carl
  • "Actually I'm kind of glad I'm not a genius anymore, too much pressure." - Sheen
  • "Jimmy...and Carl...What have I done? I've lost my two best friends in the world! What good is it to be ruler of the world if it means destroying everything you once held dear?" - Big Headed Sheen
  • "Hello, and welcome to advanced engineering. My name, Professor Sheen, and I shall be learning you today." - Sheen's last lines



  • Sheen firmly believes that Ultra Lord is real, even as a god.
  • Sheen becoming furious enough to kill his own friends and regretting it when he actually does is probably a reference to the story, "A King and His Hawk", where the king regrets murdering his dear friend, who saved him from being poisoned.
  • Sam claims that there are 12,082 beans in the jar, but they're not modeled correctly. 
  • On the test Sheen fails at the start of the episode, he mentions Ultra Lord defeated Megalon, a beetle-like Kaiju, that was actually defeated by Godzilla with the help of Jet Jaguar in "Godzilla vs. Megalon."
  • This is the first time one of the protagonists becomes evil. The next will be in The Tomorrow Boys.
  • This is the third time a character changes and then goes back to normal. The first was in Normal Boy and the second was in Make Room for Daddy-O
  • This is Nick's first appearance since Make Room for Daddy-O (not counting background appearances), as he is now a supporting character. 
  • Judy is briefly seen in this episode when Sheen goes into town with his new brain power.
  • Goddard makes a cameo in this episode when Sheen beats him at chess.
  • Captain Betty makes a cameo at the Candy Bar.
  • Sheen says "Ex-squeeze me," like Jar Jar Binks from Star Wars does.
  • This episode is ranked #72 during the "Top 100 Greatest Moments In Nicktoon History".
  • This episode reveals that Sheen had an IQ of 32 prior to putting on the Brain Gain Helmet.
  • Sheen's answers on the test were:
    • "Ultra Lord is the father of the whole planet"
    • "Episode 56-4 when Ultra Lord beat Megalon playing chess. His score was 4"
    • "On Planet Xarcatan where Ultra Lord goes on vacation"
    • "A dragon wanted to use it as a hat, but it was too small" 
    • "Ultra Lord of course"
  • The scenes from the Ultra Lord Show are from Ultra Sheen.
  • When Sheen's head grows, he resembles Hector Hammond, an antagonist from D.C Comics.
  • Although this episode was released in 2004, you can actually see "Copyright 2003 Viacom International, Inc." at the end of the credits. This means that the episode was produced in 2003.


  • The Brain Drain already had the ability to change the IQ to a higher level, when it was used on Jimmy to restore his brain, so there was no need to modify it. 
  • Sheen saw Jimmy and Carl land next to the conveniently placed costume shop that has the Ultra Lord costume displayed in the front window, so why did he not use logical reasoning to deduce that they might be in the Ultra Lord suit? 
  • Due to the fact that only Sheen's brain was planned to grow and his entire head wasn't, it should have already exploded.
  • Sheen knows how to pronounce "IQ" in this episode, but he pronounced it as "Ick" in Stuck in the Riddle With You.
The Adventures of Jimmy Neutron: Boy Genius Season 2 episodes
A Beautiful Mine | Sorry, Wrong Era | The Retroville 9 | Grumpy Young Men | Operation: Rescue Jet Fusion | Nightmare in Retroville | Monster Hunt | Jimmy for President | Return of the Nanobots | Holly Jolly Jimmy | Love Potion 976/J | Sheen's Brain | Maternotron Knows Best | Send in the Clones | The Great Egg Heist | The Feud | Out, Darn Spotlight | The Junkman Cometh | Foul Bull | The Science Fair Affair | Men at Work | The Mighty Wheezers | Billion Dollar Boy | Win, Lose and Kaboom!
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