Suggestion 1:
Quests- bring me #item or #pet for a reward type thing. This is on a LOT of sites like DNAdopts.com , http://www.thesporkedken.com/adopt/wishingquest.php , http://subeta.net/
Suggestion 2:
Multiple Alts, instead of just the one you can have several colour alts.
Suggestion 3:
Dyes...