Martin Mystery (2003-2006) is a French/Canadian animated series based on the Italian comic book Martin Mystere, animated by the studio that brought youTotally Spies!.The series revolves around typical teens Martin Mystery, his step-sister Diana Lombard and their pal Java the Caveman, as they're sent on various missions by a secret organization known as "The Center" to investigate paranormal activity around the world.
Art Evolution: More noticeable in some ways than in others. Most obvious with Martin, who in the first season has a model just different enough to be noticeable - squarer shoulders, more rectangular head, his hair is drawn a bit differently, and it all gives him the impression of being taller and more imposing than he ended up being. He also initially had a noticeable Lantern Jaw of Justice in some shots.
Bald Women: In the episode "The Lost Tribe," Diana loses all her hair after a hair dye job goes wrong and is mistaken by a group of underground creatures as their long lost queen. She stays bald for the entire episode (and gets a wig at the the very end of the episode).
Baleful Polymorph: Occasionally, the main characters and/or a bunch of random characters will be transformed into an animal.. They all turn back at the end, obviously.
Beware the Nice Ones: Before becoming the harmless alien we know, Billy was a ruthless gladiator that went about destroying planets after he annihilated them. He returned to this stage once and boy was it a battle.
The Blank: One episode features a face-stealing doppelganger.
Body Horror: One episode had a slug-like monster possessing people. Those possessed had little maggots wriggling on them, crawling in and out of their skins. Bonus point for having the victims wear band aids once freed, on the various points where the maggots were emerging.
Body Snatcher / Grand Theft Me: Most of the heroes fall victim to this at some point but special mention goes to Martin himself who seems to get possessed more frequently.
Brainwashed and Crazy: Much like Marathon's other show Totally Spies!, this happens fairly often. For some specific examples: Martin in "The Vampire Returns", due to getting his soul sucked out by the vampire, as well as (along with Java and the teacher) in "Pirates of Doom" as a result of the cursed medallion.
Coincidental Accidental Disguise: Diana resembled the queen of an ancient race called Alpha-Omega due to two things: One, she was trying out a hair dye that caused her hair to fall out and leave a stain on her balding head, and MOM just so happened to toss her a tooth necklace (she stated it was everyone would pay attention to it instead of her head.)
Combo Platter Powers: Octavia Paine's super-monster is a synthesis of the world's most powerful monster, the end result is a creature that nearly destroyed The Center, which also resulted in the one-time use of the U-Watch's laser-firing function, which just bounced off its skin. Too bad it inherited all of those monster's weaknesses
Cute Monster Girl: In the season three finale, Diana gets mutated into a very cute lizard-girl. It helps that she is wearing a a black-red skin-tight suit which is shown to have underwater high-heel jet shoes and mask, so it is more of a high-tech suit. Those two combined make her look unusually cute in a strange way. Martin even jokingly compliments that she's only a mini-mutant because her eyes changed and she has a tail.
Christmas Episode: Featuring a wish-granting snow globe that created a pocket dimension containing a Christmas-themed village... whose inhabitants, including things like the trees, reindeer and snowmen, were actually monsters.
Dark and Troubled Past: Billy used to be a Space Pirate Warlord called Ganthar, who makes the Metroid Space Pirates (sans Ridley) look like amateurs, conquering and strip-mining planets until they were completely barren, before moving on to another unfortunate planet. But all the violence became too much for him, and he fled to Earth as the Roswell Incident alien, and does a complete Heel-Face Turn, and a complete personality 180, resulting in the Billy we know.
Demonic Possession: Fairly common - surprisingly many episodes involve a Sealed Evil in a Can trying to return to full power, gain revenge of accomplish some other evil goal by possessing the body an innocent soul, usually but not always one of our heroes.
Fantasy Kitchen Sink: Not only does the show feature creatures and legends both original and obscure from every kind of sci-fi, fantasy or folklore story imaginable, but it also likes to fuse legends together to give them new spins - resulting in things like werewolves that transport victims to another dimension, ancient demons with arcane magic trapped inside cursed websites, or witches that spread like zombies.
Jerk with a Heart of Gold: Martin is commonly one of these, nearly always putting aside his self-absorbed, childish self, in order to confront whatever monster is on the scene. As soon as the mission is over, he's back to his normal behaviour. Arguably, his annoying behaviour can become a fusion of a Keet and Jerkass, as shown with his antics in the season three finale, which pushed Diana to do a Face-Heel Turn and join a rival organization. The betrayal is repaired by the end of the two-part episode, but Martin's lack of empathy seems to still remain at the end.
Lovable Coward: Billy is meek, easily scared and doesn't do danger well. This is ironically the last thing you would expect from a former alien conqueror, but Billy is quite heavily suppressing that side of himself.
Made of Iron: Martin and Java have survived situations of where a normal person could of been sent to a hospital.
Magic Skirt: An upper body variant. In the episode where Martin and Diana hang out with their dad they're hung upside down, and Diana's t-shirt slides down but only enough to show off her navel.
The Masquerade: The Center keeps paranormal activity under wraps, though the extent and severity in which they do so depends on the season. In earlier episodes, important people and authority figures sometimes already knew about the Center and would be given the heads up whenever an agent was coming by. In later seasons, only Center agents are allowed to know anything, and Martin and Diana are always on their own.
Million-to-One Chance: As seen in The Vampire Returns, Martin shares a very rare gene with Simone's original lover, and shares his looks also.
"Return Of The Beasts" . A mad paleontologist (yes, really) uses a huge geode to create dinosaurs and send them to rampage through the city for no apparent reason. At the end, Martin tricks one to melt the geode with its acid spit (really, dinosaurs do that), which causes every dinosaur to spontaneously melt into sludge. And is when you consider that the same paleontologist created Java through the same process, yet he remains intact and joins the gang permanently. (It's a flashback episode.)
Not Blood Siblings: Martin and Diana. It doesn't make their (albeit, rare) Ship Tease moments any less Squicky. It should be noted that in the comics Diana and Martin were lovers, not siblings.
Every episode, they will go to the Center to have a briefing with MOM. MOM will be working on something. And Martin will be curious. And it will be destroyed.
In most episodes, Martin will come across some kind of strange slime - giving an excuse to use the cool teleporting sequence that comes with using the slime scanner.
At some point early in the episode, something is sent to Billy for analysis. At a later point in the episode, Billy will appear out of nowhere, scaring the heck out of the heroes (who have usually just avoided something scary) in the process, to give the results in person. He will then zip away just before things get dangerous again. This was used a lot less often during the 3rd season.
At some point, the Monster of the Week will eat/capture/brainwash/do something to either the Power Trio, Billy or M.O.M, taking them out of the episode until the end. These are always perfectly cleared up by the end of the episode, generally disappearing when the monster is dispatched. (See No Ontological Inertia above.)
Parental Favoritism: Gerard tries, but it always comes off as him liking Diana more than Martin, though he's arguably a science person, compared to Martin's enthusiasm with the paranormal, (and tendency not to do well at school), which actually matches perfectly with Diana's rational views, and high marks. But he's not above accepting the paranormal with sufficient proof, since before he finds out about The Center, he's practically hit in the face by it twice, each time Martin saves him, earning his father's respect.
Sibling Rivalry: Martin and Diana often spite each other and pick fights for little to no reason at all, though they usually know when to drop it and focus on the mission. Their fighting negatively effecting their work came up several times as a plot point, however.
Sibling Switch Squick: In the original Martin Mystere comics, Diana was Martin's love interest, and eventually wife.
Sibling Yin-Yang: In most situations, Martin and Diana are embodiments of this trope.
Talking To Herself: Teryl Rothery voices M.O.M. and voiced M.O.M.'s evil former pupil Octavia Paine in the season three finale.
Weaksauce Weakness: The fungus monsters weakness is salt. One has to wonder what he's doing in Utah if that's the case.
What the Hell, Hero?: Even if she wasn't called out on it (Martin was more upset about her snagging yet another monster from him), she was quite sadistic in detonating what looked like a nitro-glycerin explosive in a cave. Underwater. In catacombs. Which collapsed the catacombs right on top of Martin and Billy. Probably because they were underwater in the first place, they survived.