Basically, if it a petpet in it that could stand in for the real petpet, it's in this list regardless of what kind of item it is, that's just how I think lol.
These are items I am actively sourcing for pet customs.
These are items I have an idea of how I would use but have not necessarily 100% decided.
Anything not in the Tiered lists are casual wishes that I have no idea how I would use yet, ~I just think they're neat~.