Brainy is a fictional character in the Hey Arnold! TV Series.



Not very much is known about Brainy. He is a quiet, kind of creepy kid who stalks Helga around. It is confirmed that he does know about Helga's crazy romantic obsession for Arnold.

He is a very mysterious character often randomly showing up in places that are least expected whenever Helga is present, the most notable occasions being Haunted Train (in which, comically, he is the only character to witness the annual occurrence of the real haunted train) and Wheezin' Ed. This leads to one of the other kids asking him "What are you doing here?" to which he responds either with "Um...I dunno" or "Um...something?" Other than that, Brainy rarely speaks.

When on the bus he sits in the back with the rest of the geeks (Eugene, Sheena and Curly) as seen is "Rhonda's Glasses."


He is usually seen wearing a golden shirt with a white collar and brown pants underneath. He has spiky hair, wears round glasses and is constantly smiling eerily. By far, the most distinguishing traits of Brainy are his trademark wheezing and deep voice.

In The Jungle Movie, Brainy appears to have grown a mustache.



Arnold is Brainy's classmate at P.S. 118 they get along okay. Arnold once saved him and Eugene from bullies in the episode Mugged. There's one time when Arnold got mad at Brainy in Wheezin' Ed because Brainy made an unexpected visit to the cave and scared everyone including Gerald, Harold, Sid, Rhonda, Phoebe, and Helga


Gerald is Brainy's classmate at P.S. 118 and they get along good. Brainy usually plays sports with him and the other P.S. 118 students


Brainy and Harold are classmates at P.S. 118. They were able to work together in World Records and if you watch Hey Arnold! more you'll usually see them sit next to each other in class and sit together at lunch. They also get along very well.


Brainy and Stinky are classmates but don't interact a-lot

Notable Gags

  • In "Wheezin' Ed", Helga hears wheezing coming from the end of the tunnel that Arnold and her are walking in. She screams and the rest of the kids run to their location. Phoebe shines her flashlight down the tunnel and reveals Brainy. Arnold asks Brainy "What are you doing here?" Brainy replies "Um.. Something."
  • In "Haunted Train", when the lights on the train begin to flicker Helga complains that she can feel someone breathing down her neck. Each time the lights flicker on, a long black shadow is seen growing closer to Helga. Eventually when the lights go on the group discovers Brainy. Helga then throws Brainy out the train door into a muddy ditch. He is later seen sitting on a fence right before dawn when the actual haunted train goes by implying that he didn't go home after the ditch.
  • In "Operation Ruthless" Helga travels through the house of mirrors to chase Arnold and Ruth. Soon after reaching a large mirror room, wheezing is heard and Brainy's face appears in the rooms many mirrors. Helga closely listens to survey where the sound is coming from, cracking her knuckles to get ready, and after several seconds, she positions herself in the correct spot and hits Brainy in the nose.
  • In "Helga on the Couch" he is the original reason Helga has to go for her therapy session. Afterwards, he shows up while she is having one of her usual soliloquies, presenting her a plastic ring as if to propose. Helga exasperatedly asks how he managed to track her down to that specific alley, then tells him she won't hit him today, patting him briefly on the cheek and making him give her a besotted grin.




  • Interestingly, out of all the main students that are generally present in Arnold's class, Brainy is one of three students who have never had an episode based around a story or problem of their own. (The other being Joey and Sheena.) He is also one of the few who have never had their last name revealed. (Sid, Sheena, Nadine.)
  • Brainy may in fact possess skills as a DJ as he is seen on the tables in "Cool Party"
    • In The Jungle Movie, he is seen playing the pan flutes, though a little discordantly.
  • Brainy is the first student to break the student-teacher prank boundary in April Fool's Day, as he is the one who pushes Principal Wartz into the pool at the dance, snickering after he performed the act.
  • In World Records, Brainy assists Harold in achieving their own world record for longest mechanical pony ride by "getting the quarters from the very nice people."
  • Brainy is one of the four characters who definitely knows of Helga's secret love for Arnold, the other three being: Dr. Bliss, Phoebe and Lila.
  • His hair can be likened to Bart Simpson's hair, both in its spiky shape form and that the skin tone is remarkably similar. Coincidentally enough, Hey Arnold! creator, Craig Bartlett is married to Lisa Groening, the sister of Simpsons creator, Matt Groening.
  • Brainy is the only one of Arnold's classmates not to be portrayed by a child actor.
  • He is voiced by series creator Craig Bartlett, who also voices Ned.
  • Craig Bartlett has stated the he may have some supernatural quality.
  • His name (or nickname) was intended to be ironic, as he often appears by Helga at the worst possible time, gets punched (or injured otherwise), and still continues to do so.

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