Does a rock count as a pet?
If not, I have a lot of (aquatic) plants.
Mom barely let's me have my fish. If she let me have what I wanted, I would have every wall of my room filled with aquariums on the lower half and terriaums filling the upper portion of my walls. A couple of birds as well. Ooh, and a big fat cute bulldog. I'd probably convert my closet to grow bamboo for my tanks. Ooh, a cage for dwarf hamsters