I was thinking about how you have to find the items for prospector Zeke in every world (twice in khrysalis) that you would get a pet version of the item you had to find. Most of the objects could be pets (cat, oyster, lounge lizard, sock monkey, crow, khryckets, and iron butterfly). The only places this would not work in is Azteca (UFO's) and Dragonspyre (Stone roses). Another pet idea is Morganthe's spider, her spider has a very interesting design and it should be a drop in the final battle.