slimy thingy id!

[Soft]

Hey guys!
I would really appreciate some help with the id of this things I´ve got in the tank. It got a long slimy arm which can grab small grains from the sand, and it also grabs food and take it into its "tube home" (?).
What is it? A good or a bad guy?
click here for a pic of it

 

[mastou]

Its reefsafe, see this page:
http://www.melevsreef.com/id/crawls.html

/Magnus

 

[LeslieH]

Probably a spionid polychaete. Harmless.

 

[Soft]

Thanks guys!
Feels great that it´s reefsafe They´re actually fun to watch!