Sand covered worm?

[shoshowhy]

I tried searching for these but came up short.

Trying to figure out what this is. Looks like it goes through the rock in multiple parts.

The only thing in the tank so far is live sand and live rock...

There is also a large hole in the sand bed that appeared too.

 

[shoshowhy]

 

[sixty_reefer]

Amohipods burrows/caves