So, I was looking at the back of my tank recently and noticed a small hole that hadn't been there before, looking in the hole with a light revealed something was in it. Closer look, I didn't know what it was, so I took a pic:

It looks like a mollusk to me. It has a kind of mottled red and white coloration and definite eyes....gotta say first thought was "Oh my god, is that an Octopus?" But it can't be, can it?