Critter ID. worm? starfish?

[mattaytayan]

Hey guys, observed this in my nano tank of 6 months. Not causing any harm or anything but watching it is freaky, never seen anything like this in my years of reefing. More curious on just what this is. Seems to have multiple "arms" or thin worm like things that poke out and gather sand to make a sand hill. curious to see if anyone knows what it is. Saw it last week aswell and disturbed the sand where it is and didn't see anything, now it's back and has made a new hill at the same spot. Any ideas? this video was taken last night with the flow off. I assume its one organism as the arms all move together and seem to be working towards a like goal, to create the biggest hill of sand!

 

[mattaytayan]

can't get the video to upload, here's a pic, hope that's enough, its those long worm looking things in the sand

 

[Hadla]

Most likely a spaghetti worm

 

[mattaytayan]

Most likely a spaghetti worm

Looks about right, thanks!!
Should i be worried about it?

 

[EeyoreIsMySpiritAnimal]

Hair worm, and no, they are good cuc members