Marc is the smartest sibling on the team and is the 'family geek'. He also seems to be very sensitive, but tries to hide it from his brothers and almost everyone else. Marc is the smartest of WOOHP and his siblings, and even brags deeply about it to his siblings much of their annoyance. But, he also admitted that he really needs them in his life, except when Tony messes up his room, Megan hogs the bathroom, and Lee gives him atomic wedgies, in "Operation WOOCSI". When he tries to impress Sheena in "Operation Crabby Bob", Marc seems to be very nervous and is unable to tell a funny joke; when Sheena thinks he's creepy Marc seems to be deeply embarrassed and hurt. In the middle of the episode, Marc wants to change his appearance to be more 'cute' only to be caught by Megan. In the end of it Megan 'changes' his look to talk to her, Sheena says 'yes' to a date with him with Megan revealing that she hadn't changed his appearance with the gadget.
AppearanceEditNormal Look: When at school or at home, Marc wears a white long sleeve shirt under a blue half-sleeved hoodie, tan cargo pants, and blue sneakers. In both spy mode and normally, he has semi-long light brown hair and hazel eyes.
SkillsEditAs he is a genius, Marc is very talented when it comes to thinking and figuring out puzzles. When Lee isn't present, he is usually the one to fly the jet, though this role is sometimes taken by Megan. His intelligence can be used in any type of situation, though he is very practical and never just jumps into something without thinking. Though he is very smart, sometimes he can be clueless; like in Episode 16 ("Operation Grow Up"), when he was examining a piece of cloth they found during their mission with his microscope and stated to his siblings he had been searching for hours and found no clue until Megan walked up to him and took the piece of cloth and pointed out and said, "Have you tried looking at the tag, genius?", Marc blushed at his mistake. In Episode 19 ("Operation Crabby Bob"), in the end of the episode, when Marc asked Sheena out and she agreed, Marc happily told Megan "Megan she said yes!! whatever look you picked worked!! Megan smiles and showed him the mirror (one of their gadgets that changes your looks) Marc becomes shocked and said "No way" after he realizes his sister didn't change his look, Megan giggled and said to Marc "Go figure. You know for a genius, you can be pretty clueless sometimes".
Marc has several things that can make him seem weak. For instance, he gets violently sea sick. He also has a fear of clowns and heights, though he conquered them both later on.
RelationshipsEditLee: Marc sees Lee as a jock. He once stated Lee gave him wedgies and thinks Lee is immature and rude. In some episodes when Lee and Marc are paired together on a mission they usually collaborate with each other. When Marc is with Lee he seems to correct him constantly and tries to be smarter than Lee and tries to hide is sensitive nature when being with him. When Marc humiliated himself in front of his crush in the cafeteria in "Operation Crabby Bob" Lee teased him by telling him to leave the ladies to him and just keep getting the good grades. In season 2 episode "Operation Yeti" Marc gets hair on his body and gets teased by Lee, Even though Marc and Lee has thier differences, He cares about Lee and tends to protect him when he is in danger or in need of help. In some episodes the two seem to get along with each other better in some episodes especially when they tease Megan or Tony.
Megan: Marc and Megan are fraternal twins (non-identical). It is shown that he and Megan get along very well. In season 1 episode 21 "Operation Desert Rescue" Megan finds their mom's birthday necklace and when she opens it, there is a picture of the entire family and Marc and Megan are the only ones that have one arm around each others' shoulder. Usually when there is a argument or a conversation between the siblings these two seem to agree always with each other more than with their other siblings. In other episodes, they are seen with an arm or an elbow around each other, or even just standing next to each other. Marc seems to be very close to Megan and never hides his sensitive nature when he is with her, he also seems to be happy to share his feelings with Megan and knows she won't laugh at him when Lee and Tony are not around. Also it shows in season 2 episode 49 "Operation Noel's Last Stand" Megan hacked into a computer when Marc was kidnapped by a villain, with her other brothers shocked asked her when did she get good with technology and she stated that Marc taught her, showing her brothers didn't know how to operate machines and Marc only taught Megan his talented skills with machines. These two pair up with each other more often when the siblings split during their missions. They are the only siblings that are hardly never seen to fight or argue. In season 2 episode 12 "Operation Astronauts"'', Marc gets captured and wakes up in a cage with Megan, he becomes extremely happy to see her alive and hugs her.
Tony: Marc and Tony are usually the ones that play games together or Marc helping Tony with his homework. Sometimes Marc finds Tony immature and annoying especially when Tony teases him, but still gets along with Tony. He hides his sensitive side when he is around with Tony. They have their own handshake sign when they congratulate each other of their teamwork. In one episode there parents are stating that they'll move and get their own rooms. Marc seemed to be overly excited and happy that he didn't have to clean up after Tony anymore.
"Everyone in school knows; come to Marc if you need help." Marc telling Tony, in "Operation Gus-jitsu"
"Hello everyone; did you miss me?" Marc with his brain restored, in "Operation WOOCSI"
Marc: "See anything unusual? You know, besides your 13 year old brother that still needs a babysitter."
Lee: "Very funny Marc." Marc commenting on Lee's maturity, in "Operation Spy Sitter"
Marc:"I'm the family geek remember and my geek-o-meter is telling me that Jimmy is gonna use his minions to attack the competition then watch them destroy each other."
(Lee looks at the flier)
Lee:"And of course reading this flier didn't hurt either."
Marc:"Not so much." Marc and Lee in "Operation Fun and Games"
"Yes! I knew it. My brainatude never fails me!" Marc, in "Operation 50 foot Hacker"
- He had a crush on a girl named Sheena Weston in "Operation Crabby Bob".
- He and Megan are fraternal twins (they share a birthday, but they don't look anything like each other)
- Ironically, being that he is 3rd oldest, he had a deeper voice than his older brother, Lee.
- His closest sibling relationship is with Megan
- His fears were heights, clowns but later overcame them
- He easily gets seasick shown in "Operation Crabby Bob".
- Marc and Megan are the only ones in the family that have names that start with an "M"
- He is shown that he is really sensitive but tends hides it when Tony and Lee are around, but doesn't hide it from Megan when he is alone with her.
- Marc and Megan are the only ones that wear the same type of sweater except different color and Megan has a zipper in her sweater
- In some episodes, Marc and Megan have a habit putting their hands in their pockets.
- He enjoys technology and computers and always seen to be on a computer hacking information during missions
- Sometimes Marc thinks he knows everything.
- Tony stated that Marc was a vegetarian in (Operation: Pet Peeved)
- In some shots he is taller than Megan, so he might be about 5'1 or 5'2
- (Operation: Astro-Nuts) It is said Marc loves Megan more than the other siblings