Dexter's Laboratory Wiki
Screen shot 2013-05-07 at 7.08.56 PM
Gender Male
Species Mutated Chimpanzee
Family Unknown
Abilities Speech,
Superhuman physique,
Genius-level intellect,
Matter manipulation
Affiliations Monkey,
Occupation Warlord (formerly)
Interests Revenge on Humanity (formerly), Freedom
First Appearance Dial M for Monkey: Simion
Voiced By Maurice LaMarche

Simion is a minor villain in the Dexter's Laboratory segment Dial M for Monkey. He only appeared in the titular episode of the same name.

Simion was voiced by Maurice LaMarche.


Simion is a chimpanzee who was mutated by gamma rays, giving him a human-like physique and the ability to speak the human language. He wore a red dinner jacket with a purple collar and cuffs with purple pants, but after returning to the jungle, he began wearing nothing but yellow briefs.


At first, Simion seemed like a highly intelligent, but ruthless and vengeful ape unwilling to let go of his grudge against the humans who abandoned him and was bent on destroying all in his path whether they be good or evil. In truth though, deep down, Simion was simply a lonely and tragic primate whose life of torment and pain blinded him with rage, causing him to forget what true kindness and happiness were like. When Monkey showed him true kindness and what it meant to be good, Simion showed his true nature, that of a sad chimp who simply wanted to be free but became lost in his anger towards humans who never even intended for his ship to explode.


Before his mutation, Simion was an ordinary chimpanzee with the typical training that was undergone by test animals at NASA. When he came in contact with the cosmic gamma radiation, he was completely transformed into a humanoid being in peak physical condition with super intelligence that was beyond most mortal comprehension. He became a technological and biological genius capable of creating vast armies of robotic spaceships and even organic terrain and plant life.


  • Matter Manipulation: After being mutated, Simion gained the ability to create and manipulate matter merely by thought and was able to create an entire world and space armada from his thoughts.


Tragic Past[]

More than half a century ago, Simion was a regular chimpanzee who was selected as the pilot of an experimental NASA space capsule during the space race and was set to be the first monkey in space, until a crack in the ship's hull created an explosion that hurled him toward a radioactive energy imbalance. The gamma radiation altered his appearance and mind giving him an enhanced physique and intelligence. He then began training his new body and expanding his knowledge and skill through meditation, soon being able to create matter merely by thought. With his new abilities, he created a whole new world from his thoughts and once he established his empire he created an immense warship from scrap in over half a century, and assembled an army to help him destroy the world and the humans that ruined his life despite his suffering having been caused by an accident.

Dial M for Monkey: Simion[]

Simion becomes friends with Monkey

Monkey reforms Simion with his pure kindness.

After finally assembling his armada to invade Earth, he tried to recruit Monkey into joining him, believing that Monkey was as much a slave as he was. However, when Monkey showed him a true simple act of kindness with the gift of a banana given to him by Agent Honeydew, he realized that Monkey was no slave and that he had chosen his own heroic path. Now overcome with emotion, Simion tearfully realized the error of his ways and so he destroyed his army (as he had created it and his space station out of anger and vengeance) and returned to Earth with Monkey. Once there, he went to live a happy and carefree life in the wilds of the jungle. He was last seen swinging on a vine thanking his new friend for his help.



  • His name is a pun on the word "simian," the scientific term for a primate, referencing his species.
  • His voice, as portrayed by Maurice LaMarche, is an impression of legendary actor Charlton Heston, as a reference to his starring role in the original Planet of the Apes.
  • He may be a reference to the DC Comics villains Vandal Savage and Gorilla Grodd.

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