What the Dickens....?

[Avi]

This must have come in on some live rock that I recently put into the tank or on the rock that some newer coral is on. Sorry the pics aren't any clearer. The animal's pure white and you can see both sides of it since there's a reflection from the glass showing it's bottom.

http://img.photobucket.com/albums/v58/Avrumeleh/Unknown0079.jpg

http://img.photobucket.com/albums/v58/Avrumeleh/Unknown0077.jpg

I'd guess it's some kind of sea slug, but what I'm most concerned about is it's possible predatory nature. Does anyone know anything about this? Thanks

[zanemoseley]

Looks like a nudibranch, there are many kinds some good some bad, if you can't find out if its good or not I"d just ditch it.