But there's a problem with many of the more popular characters. Regardless of how much you may envision them as adults, Bart Simpson and Nelson the Bully are still children, and depicting them having a romantic encounter would look rather silly. And, if you depict them in an erotic situation, you're facing a 10-year prison sentence in the U.S.
Better to age them into teenagers into adults.
Ben Tennyson (Ben 10), who found a device that allows him to shapeshift into aliens, has appeared in four tv series (2005-2014) and several movies. But he never shapeshifted into this super-bodybuilder before fan artists discovered him.
T. J. Detweiler of the Disney Channel's Recess (2000-2003) was the leader of a band of 3rd grade buddies. Here he's grown up and beefed up so much that he's unrecognizeable except for the signature red hat. I don't know why he's tied to a tree in his underwear.
Sometimes fan artists choose rather obscure subjects. The Backyardigans (2003-2006), for preschoolers on CBS, featured a group of toddler anthropomorphic animals: a penguin, a hippopotamus, a kangaroo, and so on. This is Tyrone, the red-headed moose, turned into a buffed, morose human teenager.
More after the break.
Adventure Time (2010-) sends 10-year old Finn the Human through a magical, postapocalyptic landscape. Finn is gradually growing up as the seasons pass. But he hasn't yet reached his 20s, when, apparently, he will have massive pecs and shoulders that shred his green shirt.
All pictures borrowed from the artist galleries on deviantart.com.
See also: Gay Fan Art 1: Max Goof; Gay Fan Art 4: Ron Stoppable.