worm?

we found a worm tonight coming out from under an anemone (clown was not happy). he is huge! (well, compared to most worms ive seen) for reference the clown is about 1.5 inches. what is it? should we 'extract' it? his mouth is flat like a suction cup and he colapses into himself when he withdrawls. whatever he is, he is LONG, weve seen him poke his head out from other areas, a foot or two away.

peanut worm? i took it out, its sitting in a cup right next to me.

ETA: my only concern is he is MUCH larger than anything i read about peanut worms. when we put him back in he streched out well over one foot. i snapped a few more pics just because.
bleh, the more i learn and see on these rocks the less i want to touch them. ever.