Dexter's Laboratory Wiki
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"The Big Sister" The Big Sister
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"The Big Sister" The Big Sister
Season 1, Episode 1 (4c)
Episode name reference to/pun on: How Dexter and Dee Dee morph into various animals throughout the episode.
1995-02-26 - Pilot 'Changes'
Air date February 26, 1995 (first airing)
May 19, 1996 (second airing)
Production number 1a
Written by Genndy Tartakovsky
Directed by Genndy Tartakovsky
Craig McCracken and Paul Rudish (Art direction)

Changes (originally called Dexter's Laboratory) is the pilot episode of Dexter's Laboratory. It first aired on February 26, 1995 as part of Cartoon Network's What a Cartoon! series, and later on May 16, 1996 as the first segment of the fourth episode of season one.

In this episode, Dexter invents a remote control that transforms people into different kinds of animals every time the button on it is pressed, only for Dee Dee to get ahold of it.


On a school morning, Mom asks Dee Dee to go and see if her younger brother Dexter is ready to go to school. Dee Dee readily agrees to this and dances to Dexter's room door. After knocking, there is no response and the door is locked. Dee Dee then uses an express credit card to break the lock and enter Dexter's room. She races into Dexter's laboratory and finds him at work on a remote. Delighted, Dexter goes to put his newest invention, a remote, on a pedestal. Angered, Dexter tries to remove Dee Dee from his lab, but she instead causes chaos by rearranging a DNA model and knocking over several beakers and flasks as she races through the laboratory, with Dexter giving chase.

As Dexter tries to stop Dee Dee, he ends up being thrown around and crushed by many of his inventions. Dee Dee's chaos is suddenly interrupted as she sees her doll on an operating table. Angered, Dee Dee makes Dexter back into a pedestal and causes the invention to fly into her hands. Dexter pleads for mercy, but Dee Dee presses the button on the remote, causing Dexter to transform into a bunny. In retaliation, Dexter transforms Dee Dee into a bullfrog. Dexter then explains the process of how the remote works to Dee Dee, who transforms him into various animals while doing so.

As he nears Dee Dee, Dexter snaps the remote out of her hand and transforms her into a tiger. A fight ensues between the siblings, with Dee Dee turning Dexter into more animals as she chases him out of his own laboratory. After more transformations, Dexter and Dee Dee, both as a beaver and dinosaur respectively, go to prepare for school and then meet up with Mom in the kitchen as a rooster and a bear. Angered by their antics, Mom then goes to Dexter's room to check up on Dexter and Dee Dee, who are a snail and a turtle. They both race to press the button on the remote and are successful just as Mom opens the door. She then tells them to stop playing around and get downstairs before they miss their bus.

Dee Dee, who is now in Dexter's body, dances out of his room after telling him that he'll be an "icky, yucky spider" to the bus, while Dexter, who is now Dee Dee, just goes along with it since he's already been everything else.



  • Dexter, Dee Dee, and Mom's first debut on screen.
  • This is the first pilot episode of Dexter's Laboratory. The other three being The Big Sister, Old Man Dexter, and Dumb Like Dee Dee.
  • Mom is the first character to speak in this episode, making her the first character in the entire series to speak. She is also the first character to appear on-screen.

Cultural References[]

  • This episode is quite similar to a Calvin and Hobbes storyline where Calvin invents a transmogrifier machine where during an argument between them they transform each other into various animals.
  • When Dee Dee opened Dexter's door, she used an express card.

Episode Connections[]

  • The newspaper delivery guy at the beginning of the episode is seen again in the episode "Last But Not Beast".
  • This episode was referenced to in the episode "Rude Removal" when Dee Dee asked Dexter if he was building a machine that changed people into animals.


  • When Dexter is turned into a bunny, his shadow is shown to be in his human form.
  • Most of Dexter's transformations don't have him wearing glasses, but as he leaves his room while transformed into a penguin, he has his glasses on.
  • When Dexter charges into his room door as a ram, he leaves a big hole behind. However, in the next few frames, the hole is not there.
  • When Dee Dee opened her door, it revealed that the inside of her room was teal, but in most episodes, such as "Dee Dee's Room", her room was pink.

Production Notes[]

  • This episode was originally titled "Dexter's Laboratory" before it was later renamed to "Changes" by the time Dexter's Laboratory became a full TV series, though the episode's on-screen title still reads "Dexter's Laboratory".
  • When Changes aired as the third part of the fourth episode in season 1, its sister episode, Dial M for Monkey: Barbequor, was later replaced with Dexter's Lab: A Story due to copyright infringement over the character Silver Spooner.
  • This is the only time Advantage Audio did the sound editing for anything Dexter's Laboratory-related. As a result, the sound effects are very different from future episode; most notable are the lack of any classic Hanna-Barbera sound effects. Beginning with "The Big Sister", Twenty-First Century Entertainment takes over the sound editing up until after "Ego Trip" (to which Hacienda Post, who would eventually acquire and fold Twenty-First Century Entertainment, takes over the sound editing for the revival seasons).