Green/Yellow Worm Thing

[Devin R.]

I was looking at my live rock to see if anything new showed up, because it's a newly established aquarium. I noticed something weird and green with tentacle like things. I can't really tell if it's moving with the current or moving on it's own so I really need this thing ID'd so I can remove it right away if it's bad. Please help!

Here's a link to the video (Change quality if it doesn't start in HD!):
https://drive.google.com/?tab=wo&authuser=0#my-drive

 

[Betta132]

I can't see the video... It's a link to the drive of whoever clicks it.
Does it have a tangle of tentacles at one end? Probably just a peanut or spaghetti worm. Harmless gunk-eaters that creep around, hide in rock, and pick up bits of gunk. They're cool to watch!