Could I make a request to the legalities of the contest? In addition to the prize for winning, could a stipulation be placed that the winners name ( a "created by......be attached to the creation for all uses henceforth? Also any submitters gain the same privilege IF their work is used in latter material?
This would grant the winner some nice bragging rights, and sweeten the deal for participants even if they do not win.
Including your info with the character each time it's used most likely isn't going to happen.
You will get credit, in the ORDER OF BATTLE section of the annual CanJoeCon Comic that comes with the con set should this character become a full fledged "Joe Canuck used" character. In the 2009 one, whoever did the bio for each character had it marked as so. Example : Larry Hama - Snowbank, Chacal Noir. Ryan Costello Jr. - Back-Stop, etc.
If you need something to sweeten the deal, then maybe this contest isn't for you? I think the prizes are pretty cool in themselves... a bunch of Joe Toys, and your creation in one of our comics. You'll obviously get the credit in the comic - so that alone should be "sweet" enough. ;-)