Dexter's Laboratory Wiki
Douglas E. Mordecai III
Gender Male
Species Human
Family Douglas E. Mordecai II (unseen father)
Douglas E. Mordecai I (unseen grandfather)
Occupation Student at Huber Elementary
Interests Science, Robotics
First Appearance The Bus Boy
Voiced By Tom Kenny

Douglas E. Mordecai III is one of Dexter's best friends. He attends school with him and is similarly geeky. He is voiced by Tom Kenny.


Douglas is a friendly boy with geeky tendencies who shares much in common with Dexter, and while they are both very intelligent, he does not seem to be as smart as Dexter. It's unknown if he knows about Dexter's laboratory since he was never seen in it, but it is a possibility since he knows Dexter's work. E.G.: An Interdimensional Portal to the Multiverse from the episode "Framed". Also, in the episode "Dexter's Rival", Mandark claims to have learned about Dexter's lab from a third party, and although Douglas is not mentioned in the episode, he is most likely the only person in school Dexter would trust with that knowledge, indicating that the two have a very close friendship.


The Bus Boy[]

Douglas and Dexter are seen on the bus showing off their items that they prepared for their big test. When Dexter shows off his #2 pencil, it is taken by Gwen & Becky who end up losing it in the back of the bus, much to everyone's horror. Before heading into the back to get his pencil back, everyone tells Dexter the many legends of Billy Bloomberg, including Douglas, who explains that Billy had been sucked into an Interdimensional Portal to the Multiverse that opened up in the back of the bus. Regardless, Dexter went into the back of the bus and discovered that Billy had simply gotten stuck on some gum many years ago and proceeded to save him, much to everyone's amazement.


He and Dexter are seen listening to a science recording, naturally giggling at "Chapter 8: Reproduction". After Dexter becomes popular, he ends up abandoning Douglas, but after Dexter learns the error of his ways, Douglas gladly welcomes him back.

Would You Like That in the Can[]

Dexter shows Douglas his schematic for an invention, which Dexter puts in his lunchbox for safe keeping. But when a girl accidentally takes Dexter’s lunchbox and brings it into the girls bathroom, the two sneak in there dressed as girls. Once in the girls room they find a magical realm in the last stall. After Dexter finds his lunchbox, he and Douglas get ready to leave the bathroom, when Douglas needs use it. However, as Douglas forgot to put the toilet seat down they are discovered, and the girls prepare to beat them up. Luckily, Dexter is able to save them by threatening to break their doll, so the girls let them leave. However, as Dexter and Douglas triumphantly exit the girls bathroom, they are humiliated by jocks, due to them still wearing their disguises.

Episode Appearances[]


  • Although Dexter is shown to have a number of friends throughout the show, Douglas is the only one to appear in more than one episode, with the others being one-offs.
  • In season 2, everyone called him by his first name. Since season 3, everyone addressed him by his last name.
  • The shoes Douglas wore in season 2 are a reference to the sports brand Adidas.