jmtrtt: I believe I offered a "Future Imperfect" challenge in one of the recent polls, which was similar to what you're suggesting. I think it got a vote or two, but it didn't come out on top. We had a "Brat Pack" contest a while back that focused on child/teen characters as well. Still, a contest focusing on making older/younger versions of existing characters could be a fun challenge, and offering both age extremes would provide a lot of creative flexibility.
Here's another couple of ideas I came up with:
Figure Realm Mascot Custom Contest:
Create an original character that you feel represents the Figure Realm web site/community/spirit. In addition to it being an original character, the only other requirement is that you have to put the words "Figure Realm" on it somewhere, somehow (maybe a tattoo, written across a T-shirt, sculpted in relief on a shield accessory, etc., it's up to you.) Show Captain Coder and everybody else how you feel about our community with your Figure Realm mascot!
Cancelled Figures Custom Contest:
Any toy that was planned, but cancelled, before they were ever put into mass production and released. Things like Legendary Comic Book Heroes Series 3, the henchmen pack-ins for Marvel Legends Series 13 (except for the Brood and Skrull, those were released as Marvel Select figures), Spawn Series 35: Robot Wars, etc. There has to be documented proof (prototype photos, concept sketches, etc.), the unreleased figures can't be unsubstantiated rumors. Maybe I, or someone else, suggested this one before, I kind of got deja vu while I was writing it.