What is this on my Frogspawn

[JRamey24]

I started noticing these little curly things on my rock and Frogspawn about a month ago. They have little strings that come out of them from time to time. I removed one and it had a hole burrowed into the skeleton. I feel like I may have damaged the coral doing this. Help? First picture is before and second is after removal.

 

[sixty_reefer]

Picture ain’t very clear, worth googling spyroid worms and vermitid snails common hitchhikers that look similar to the blur in the pic.

 

[reef lover]

Spirorbid worms. Harmless.