Hi! I'm relatively new here and am one of those people who loves to collect and have at least one of every critter I can get my mitts on! Even (and especially) the older ones. This, as we all know, requires filling the wishlist with every pet missed from the past and keeping up on the newer ones too. However, to do this, you have to add one pet at a time. This gets extremely tedious after you've completely cleared the fourth or so year into the past.
Thus, I'd like to propose an Auto-Fill feature for the wishlist. It could be an optional check-box that, once checked and confirmed, adds in any pet that isn't yet in your collection to your wishlist. It would be infinitely easier for completionist collectors like myself to figure out which pets we're missing in the long run!