Hang on.Can you see if it's got lots of legs?
Assuming they are legs (and I'm still not entirely sure), there are too many for it to be an insect (they have 3 pairs) which makes it a crustacean, and most likely <"Asellus">.Looks like some sort of Nymph
That was my first thought and that the "legs" are the branching intestine.for me that's a Snail Leech