I can't remember if i've done it in the past and how it worked out. For example, if i already redeemed a code for a pet groundhog and made the pet last year but then I find the ultra rare adopt a pet again that have the code for groundhog, what happens when i redeem that code on my account? Will I again be rewarded with the ability to make that pet? or will it see ive already unlocked it and just give me some gems or something? I would ask AJHQ but they've given me wrong answers in the past so i'd prefer replies from actual players that have done this and know first hand.