Pest? Strange Worm I found

[saboken]

I found this worm on some new zoas before I dipped them I am going to save it in a unused tank till I can ID if it's good or bad before I removed it from the Zoas it had long hair like Antennas sticking out with bright green dots on the ends anyone ever see this thing before? is it good or bad?

 

[mcgyvr]

looks like some sort of sea slug/coral,sponge predator..
KILL IT

http://www.chucksaddiction.com/Hitchsnails.html
see Berthellina citrina .. something like that.

 

[MARINECRITTERS]

I forget the name of those but they are harmless, I have hundreds of them in my tank, they just graze on algae.