|“||What a fine day...for Science!||”|
|Voiced by||Candi Milo|
Dexter is the younger (but more intelligent) brother of Dee Dee. He is a boy genius and is fully devoted to science, but he is also very arrogant and takes great pride in his intelligence. In the series, he has a lab behind his bookshelf, where he performs experiments and creates inventions, which usually leads to trouble for him and his surroundings. His lab is usually devastated by his sister Dee Dee who just wants to play with his inventions.
Prior to FusionFall, Dexter has asserted himself as a world famous genius and inventor, and can sometimes seem like the leader in the fight against Fuse. Before he hit his teenage years, Dexter founded his company, DexLabs, and became more and more withdrawn therefore after. Computress, Dexter's robotic assistant became his only companion.
In the manga, it states that after the first Terrafusers landed on Earth, Dexter finally came out of seclusion and teamed up with ten-year-old Ben Tennyson, Professor Utonium, Blossom, Bubbles, Dee Dee, Numbuh Five, Numbuh Two, Mac, Bloo, and his arch-rival, Mandark, to defend Foster's Home for Imaginary Friends from the Fusion Spawn invaders. Dexter developed plans for an Electronic Pulse Cannon to disable the Terrafusers. Unfortunately, two key parts to the EPC were in the custody of both his nemesis, Mandark, and the villain, Mojo Jojo. Mojo's part was recovered without a hitch, but Mandark refused to hand over his part unless he could oversee the construction of the EPC. Dexter reluctantly agreed and formed an uneasy alliance with his rival. Unfortunately, Mandark was distracted by his infatuation with Dee Dee, and made a fatal error in programing the EPC, causing it to jam at a crucial moment. Dexter was able to fix the error, and fired the cannon at the main Terrafuser, but not before it shot a signal that brought Planet Fusion to Earth.
At an unspecified time, the Hero has enlisted in a DexLabs time travel project. Before Dexter can program a destination into the machine, Dee Dee messes up the project (with her most famous line, "Ooooh! What does this button do?"), and sends the Hero into the far future where Planet Fusion's invasion has almost completely overtaken Earth. Dexter appears briefly and helps the Hero fight off his/her first Fusion, Fusion Buttercup. He is seen earlier helping Numbuh One, but disappears after Tech Square is devoured by the Fusion Invasion, signifying that he was lost after Tech Square fell. Shortly after on, a holographic message comes from Dexter for the characters to help the Hero back to the past.
Dexter can be found in Tech Square in front of DexLabs, alongside Computress. He has constructed a home for his parents on top of his company building in order to protect them after Fusion Spawns started appearing around his old house in Genius Grove. However, his old lab there is still a Fusion target. His robots, the Dexbots, are found all over the world.
Dexter as a Guide
Dexter serves as one of the four guides players can choose to take missions from.He aims to find out just what has happened to the heroes who have disappeared during the Fusion Invasion, using an alien device known as the Power Level Tracker. Eventually, it is revealed that Fusion Demongo, with his counterpart's stolen powers, is the cause of the disappearances. With the enlisted help of Samurai Jack, the player rescues and frees the missing heroes. In the aftermath, it is revealed that Aku, Jack's mortal enemy, is lurking in the shadows.
Dexter also appears to have a dislike of imaginary friends, like Mandark's hatred of magic. It is more likely, however, that he was mad only at Coco for destroying one of his machines and at Cheese for disabling the shields during an important battle. (Very likely these displays of impatience resulted more from his lack of tolerance for annoying individuals such as Dee Dee than for Imaginary Friends as such, meaning he would show no hate for Wilt or Eduardo).
Echo Echo stated during the Birthday Bash that Dexter made a device that lets Ben send his aliens around the world. How he had done this without damaging the Omnitrix is still unknown. As of February 2011, Dexter can be seen at Mt. Neverest, telling recruits what his guide missions involve.
In FusionFall Heroes, Dexter has discovered an element known as Dextronium, he and other heroes use it to combat Fusion monsters. His basic weaponry consists of four robotic arms on his back, each armed with a blaster pistol, as well as a large robot arm for close quarters.
- In the series he is short and is eight years old, but in FusionFall, he is around 13-15 and as tall as a teenager. Because of this, his Nano resembles his cartoon form more than he does (mostly in size).
- He is one of the four NPCs to give out two Nano missions. The other three are Ben, Grandpa Max, and Lance.
- In the show, Dexter has no hair on the back of his head, but in FusionFall, he and his counterpart Nano do.
- In FusionFall Heroes, his pupils are not shown under his glasses, unlike in FusionFall.
- The robot arm he uses is FusionFall Heroes appears to be the same one he used in the Future while fighting Fusion Buttercup.