A spider-man relative?

[dtum]

I've got this weird dude in my tank, first I thought that my hammer coral was releasing this string of mucus, but then I noticed that there's another creature that is sitting in the branch part of the coral. I can see that there's a hollow orifice and there's someone inside, there's also a cap that it can use to close the orifice. And this weird creature constantly releases this string.

http://i1191.photobucket.com/albums/z464/tumanov/Winterfell%20Reef/DSC01230.jpg

Any ideas on who this is?

[Misled]

Vermitid snail

[MARINECRITTERS]

Vermitid snail

+1, remove it by sticking something over the tube ( superglue/aquarium glue )
If you don't they will spread and irritate coral.

[bpcardona]

+1 I have been supergluing the ones I can get to.

[Misled]

If you don't they will spread

When they do, the small ones are very sharp. They can very easily cut you.

[kingfisher62]

When they do, the small ones are very sharp. They can very easily cut you.
And cause a nasty infection!

Those webs really do bother the corals. When ever I kick up any detrius in my tank you can see those webs from across the room. Not single strands like in the first picture but full fledged webs.

Time to do a little cleaning in my tank.

[dmh41532]

vermetids nearly killed my hammer and did kill my cristata, a dab of superglue should take care of it.