Hitchiker in tank? and new thing growing on rock?

[hakan]

Hey guys this urchin looking thing is hanging off my new turbo snail. Any idea what it could be? first time seeing it in my tank.

also the little plant growing on my live rock. Would anyone happen to know what that might also be and is it safe in there or should I get rid of it? When i get close to it it runs back into its little hole.

Thanks heaps

 

[mr_X]

yes, that appears to be an urchin. the second picture is a tube worm, commonly called a feather duster. both are safe to keep.

 

[hakan]

Cool thanks heaps,