Can any ID these "WORMS" ??

[tangtang clown]

So the story starts out with my friend having a super clean 75 gallon with brain corals and leathers with various fish. Long story short his tank was the reason I got into reefing 3 years ago. Fast forward three years to 6 months ago and I helped my friend upgrade from his 75 to a 110 extra tall. After that he started neglecting his tank due to work and monetary supllies, even though I offered to help him maintain his tank he declined numerous times, PRIDE which is understandable as I would not want anyone taking care of my tank either. So two weeks ago my friends tank was soooooo disgusting you couldn't even see through the front or side panels due to algae and other disgusting things. Needless to say he lost his brain, leather, and all his corals. The only fish he has left is one bad A$$ clown who survived the STORM. He decided to do a major cleaning two weeks ago which involved scraping the glass and removing every rock, scrubbing them and rinsing in SW. The day after cleaning everything, he noticed these guys crawling around:

Has anyone ever seen anything similar? If so, what are they?

 

[shrimphead]

peanut worm, or maybe even a sausage worm

 

[tangtang clown]

Are they good or bad? Where do they come from?

 

[Sk8r]

They're fine.
From the rock. 'Live' rock can contain a lot of things. Most are good. The notable bad worm is the eunicid: google that, and look at the tentacles on the head. All other worms tend to be good. The reverse proportion occurs with hitchhiking crabs and nudibranchs.

 

[tangtang clown]

Thanks. My buddy keeps saying he needs to get them out asap, but I will tell him to keep them in the tank so he can brag about 3 live items in there. What a shame.