Melissa's Octopus and Other Unsuitable Pets

There are certain animals that make suitable pets, like a cat, a dog, or a guinea pig. Then there are others that make, well, unusual pets, like an octopus, a warthog, or an elephant. They're too large, too messy, and maybe a tad too free-spirited with a tendency to break things like tables, floors, and even ceilings. But can you guess what makes the most unsuitable pet ever?