Marsupilami (or "Mars" as some call him for short) is an incredibally rare animal, and his name is the same as his species (loosely translated as French for "Marsupial Friend"). Mars has an incredibally long prehensal tail that can be used as a tool as well as a toy, as he change its shape into any form he wants from a spring-coil so he can expand his jumping distance (when that happens, his tail makes a "boing" sound) to a crude-yet-effective wreckingball for giving his enemies a good whacking. Though in the comics that his species was introduced in claim he's from South America (and some cartoonists outside Disney's work, which illustratingly claim he's there now, married with triplet young), Mars makes himself at home in the jungles of Africa. It's not really clear how he got there in the first place, though one comicbook issue tell the story of how he escaped from a Poacher's Oceanliner with a gorilla... no doubt that's how he met Maurice. Mars claims he's the last of his kind, but never lets that get him down. Although, considering the odds of the Disney version leaving some things out (like how he learned to talk like a human), we can never be so sure. For all we know, he might be one of the first true marsupilami africanus, on account of his mane.
Nobody knows for sure how he ended up in Africa, but according to a "lost episode" in the Dutch language, he and Maurice known each other since they were really little (they act like todders in the flashback about it, in the episode translated as "Young and Nestless", but with animal development, they might've been younger then that... most likely, only babies). During that time, Mars lived in a well put-together treehouse (Maurice shares residence) and enjoys reading a collection of comicbooks, which proves he's most likely raised by humans and learns there language. His caregivers were probably off-screen characters, as the only human shown in that episode was a burly boy (most likely grew up to be Norman the poacher) who uses games to get rid of the animals so he can raid their treehouse and steal the comics, but even as a youth, Mars' tail is used to get himself and Maurice out of danger and back home. (kid Norman was rolled away on his own tricycle in the end.)
In the first known episode of the Disney version, Working Class Mars, Mars continues to attempt fitting into the human world as he (over)entusiasticly attempts to get and hold a job, and continues to keep Maurice by his side as his colledge, partner, best friend, and curtified PHD (short for "Pretty Huge Dope").
Mars tends be quite the wisecracker, as he seems to make jokes about several situations he gets into, but that gets him into trouble. On "Marsupilami meets Dr.Normanstine" he jokes about the mad scientist's lab ("All it needs is a monster with bolts in his neck and a zipper on his face. Ha!") before meeting the creature he was only kidding about ("Me and my big mouth!"), even the non-Disney version (who is a father of three) tends to show that traint, as along with getting on his wife's badside and needing to appologize on numerous occasions, he even got his human friends in trouble with a prank he caused using a Marsupilami-to-Human Translator (only the Disney verison can truely talk, and might do well as a translator between humans and animals).
Mars might be an adult marsupilami, but he has the naive point-of-view of a human child, most likely a pre-teen boy, as he tends to let Maurice (his dim-witted gorilla friend who loves to lunch) give second opinions in judging character with a "seal of approval", and but with that kind of charisma, Mars has instincts strong for his species when it comes to romancing and social skills (see episode "Prime Mates Forever") and can prove himself smart and secourceful, especially in those "last straw" moments, usually if somebody threatens his home and/or friends. He's even optimistic, as he lets nothing, not even the time he lost his tail, get him down... until Maurice, his "best buddy", disappears as well. After being toyed-around with by Norman in his Witch Doctor gimmic, Mars asks if the source of his powers, the magic mirror-ra, can make a coconunt fall out of the sky, and Norman makes a tree-ful of coconuts fall... on himself! When Mars stole the mirror, he wished back Maurice before even considering to restore his "favorite appendage". (Witch Doctor is Which)
Although caring enough to help out an enemy when most neccesary (like when Edwardo the leopard got a thorn in his paw), Mars can be kind of an egomaniac at times (though the more observant claim that's an exaduration since he cares alot about being the center of attention and how he appears), as he believes politicians use their brains less then he does, and after he ate a bad melon and started to lose his spots, he paniced claiming that he's nobody but a "little-yellow-guy with a long tail" without one (and the one spot remaining, on the wrist of his right arm, is his favorite spot). Then again, dark areas of his species' fur are a sign of both health and statis, so it's normal for his kind (at least in the sub-species that have spots) to see it as something serious. He can be a bit of a city-boy/jerkwad sometimes, as seen by the fact he teasingly calls Stewert the elephant "Stewie" on purpose, no matter how much the panic-prone pachiderm corrects him (to be extra cruel, he called Stewert "Chuck" atleast one). But wether he's good or bad (mostly good with a hint of mischief), he's a marsupilami like any before him, as his diet is many fruits, veggies, and fish... pirahna, especially... and he's noted for saying "Houba!" (the call of the male of his species), especially when he's very excited or amazed about something... he even snores it.
Like any of his kind, Mars lives in a nest high in the trees that opens and shuts like a clamshell, although he uses strudy sticks instead of flexable bamboo rods (most likely a precaution, as Stewart climbs up to the nest in fear, and breaks it goodness knows how offen... Mars says he lacks insurance for his home). Another difference is that, instead of feathers, his bedding is made out of savanna grass, and judging by the compassionary jesters on Toucan alway Get what You Want, this is not because of allergies, but rather because, if in his choice, he'd hurt no living thing (well, that, and it's the African Jungle, so it might just be a popular mattress style).It's a small nest... only big enough to use his tail as a porch swing, yet small enough for one marsupilami, as he believes he's the last of his kind (if there's a film based on the Disney Version, he's in for a surprise). When his nest was removed from the tree and used as a suitcase, it has stickers on the outershell from all over the world: I Heart NYC, the Eyeffel Tower (Paris), a man with a tall fuzzy hat (London, or Russia), and even a Mickey Mouse Sticker (he's been to one of the Disney Theme Parks).