I mean, we have our pigs and our chickens (if we catch them and imprison them in our backyards), and we have our magic learning rock, but what about a pet.
A dog, a cat, a fish... something simple that either lives at our house or follows us around (maybe the fish wouldn't, that might mean a short life span) that we train. To do stuff. Useful stuff (like dig, or fertilize trees).
I think that might be kinda useful, or just plain cute. Might get a little flash heavy at times if they follow us around everywhere, but that depends on the pet animation I would suppose.
That or pets can only wander in the area where we have a house. For example: I live in Marrakesh Meadows. Therefore, my pet can wander where the houses are (my particular block) and wander in the meadow when I go out into it, but can't follow me to other streets outside Marrakesh Meadow (even if I teleport). If I move, the pet goes with me and the same parameters apply to the new location.