Played by: Matthew LawrenceThe main protagonist of the series. Sam is the lead guitarist of a teen rock band called Team Samurai. In a freak accident with his personal computer, Sam gains the ability to transform into a cybernetic superhero Servo, a guardian tasked with saving the world from the evil digital menace Kilokhan.
- Chivalrous Pervert: Despite his heroism, Sam is not above G-rated sexual deviance.
- Finishing Move: Subverted in that Servo has multiple finishing moves all connected to his Grid Power. He can charge up energy and shoot it through the blaster on his left gauntlet, he can generate a crescent-shaped beam with his hands and throw it at the virus, or he charge his power into his feet and jump kick the virus.
- The Hero
- I Just Want to Be Normal: Sam goes through this when he bemoans his slipping grades, lack of time with his band and girlfriend.
- Weapon of Choice:
- Wake Up, Go to School, Save the World
Played by: Kevin CastroTeam Samurai's drummer and the school's best player on the football team. Tanker is eager for a good battle and a good meal. When not fighting, drumming, or eating, he longs to be with Sydney.
- Big Eater: Lack of food will drive him crazy.
- Book Dumb: Tanker isn't by any means stupid, but grades are not one of his priorities.
- The Lancer
- Lovable Jock: One of nicest athletes in school. He only becomes a Jerk Jock where Malcolm is concerned. However, Malcolm deserves whatever Tanker wants to dish out.
- No Last Name Given
- Reluctant Hero: When Sam is unavailable to be Servo, Tanker does not feel up to the task.
- Tank Goodness
- Unresolved Sexual Tension: With Sydney
Sydney "Syd" Forrester/Borr
Played by: Robin Mary FlorenceKeyboard player, vocals, and computer genius. The tomboyish Syd is constantly maintaining Servo's programs, keeping Sam in top form.
- Ace Pilot: When in Syberspace.
- Nice Hat: Constantly wearing hats that were in style at the time.
- The Smart Girl
- The Smurfette Principle
- This Is a Drill: Her main weapon as Borr.
- Tomboyish Name
Played by: Troy SlatenBass player and a total space case.
- Ace Pilot: When he goes into Syberspace.
- Cloud Cuckoo Lander
- Cool Plane
- Genius Ditz: For all his quirks, he's an outstanding bass player (the band was originally hoping to recruit Amp's brother for his talent, only to learn that Amp taught his brother how to play), and an Ace Pilot in Syberspace.
- Hidden Depths: Despite his outlandish non-sequiturs, Amp can be very insightful.
- Put on a Bus
- Teacher/Student Romance: He develops a one-sided crush on a teacher, but nothing of this crush is ever mentioned again.
Lucky London/Vitor II
Played by: RembrantAmp's replacement with a love for surfing.
- Ace Pilot: In Syberspace.
- Dumb Blonde: Male variant.
- Cool Plane
- Suspiciously Similar Substitute: He receives no formal introductory episode. He just shows up when Team Samurai needs another person like Amp.
- Surfer Dude
Voiced by: Tim CurryThe main villain of the show. Kilokhan is a rogue military artificial intelligence hell bent on ruling the world. He uses his powers to bring Malcolm's drawings to life as Mega Virus Monsters to wreck havoc on the digital world.
- Bad Ass Baritone: Tim Curry at his best, folks.
- Big Bad
- Cool and Unusual Punishment: Kilokhan has come up with various creative but non-lethal punishments for Malcolm whenever one of his viruses is destroyed. These have ranged from hypnotizing Malcolm to confess that he's been cutting class and getting detention to zapping all of Malcolm's hair off.
- Creative Sterility: Despite his powers, he lacks the creative abilities to design and program viruses. Hence he needs Malcolm to design the viruses for him.
- Evil Laugh
- Evil Overlord: Of the digital world as he always proclaims.
- Non-Action Big Bad: He does nothing more than bark orders at Malcolm, bring monsters to life, and curse at Servo...right up until he personally engages Servo and shows just how lucky Team Samurai is that he's never tried to fight them personally before now.
- Verbal Tic: After an Evil Laugh, he will sometimes utter a phrase appropriate to the situation.
- Vile Villain, Saccharine Show
Played by: Glen BeaudinA classmate from Sam's school. Malcolm is lonely kid who wears black and has artistic talent. When he and Kilokhan form an alliance, Malcolm uses Kilokhan's abilities to bring his monsters to life to make others miserable.
- Adaptational Villainy: Unlike his Japanese counterpart, Malcolm wasn't brainwashed into creating monsters for the Big Bad.
- Even Evil Has Standards: Although Malcolm loves seeing Team Samurai humiliated, and doesn't necessarily care when other people's lives are endangered, but he draws the line at Kilokahn trying to use a virus to activate America's nuclear arsenal to start World War III.
- Evil Is Petty: Much to Kilokhan's chagrin.
- Heel–Face Turn: He became this in what was intended to be the Grand Finale. Had the new Gridman series been produced, Malcolm would have become the new Servo, just as his Japanese counterpart was intended to be the new Gridman.
- The Rival: He competes for Sam's girlfriend Jennifer.
- Loners Are Freaks: He's often treated as such by the other characters, which gives him some basis for his bitterness.
- Mad Artist: He's not insane, but he's bitter, withdrawn and antisocial. He's also a very talented sketch artist.
- Vile Villain, Saccharine Show: Less so than Kilokhan. It becomes horrific when you realize that any 21st century teen who exhibits the same kind of behavior as Malcolm does is not to be taken lightly.
- You Have Outlived Your Usefulness: Once Kilokhan has Team Samurai at his mercy, he no longer needs Malcolm.