I was watching my Mystery snails eat some algae wafers when I saw a worm like creature suctioned onto one of their shells. I took the snail and pulled the worm like creature off with tweezers. It is now in a small container of water. It is small and brown. It is squirming around a lot and it suctioned onto the tweezers and it took a while to get it off the tweezers. It looks flat and it seems to be changing shapes from a long strand to bunching up in a little ball. I will post a picture tomorrow but I'm really scared there will be more of them and they will harm my fish.