Although there are already achievements for collecting non-combat pets, perhaps it could specialize further by having an achievement that rewards the player for collecting all 4 flavors of whelp (Although I would highly recommend making a Bronze Whelp that is a rare drop from Tanaris mobs) and then maybe take it a step further where the player can get an achievement for having the Netherwhelp and Frost Wyrm Whelp instead of piling all the whelps into one achievement, so those without Collector's Editions can also get a Whelp achievement.

You could also take this in other directions as well, like maybe Collect All Mechanical Pets, or Collect All Dragonhawks.

Many Whelps?