I need help identifying what the heck this is!

[Mcgrew]

It’s growing mega fast and originally came hidden on a green star polyp rock I bought, I can clear it all off the gsp (by taking the rock out and manually pulling it off!) but it grows back in a week and dominates the rock again, it’s also spread to a nearby rock and all that has grown in one week from a single polyp!!!

I have no idea what it is though so no idea how to control, local fish shop have no idea either and I can’t seem to get better photos of it to showcase it

I’m hoping someone here knows what it is and has advice

 

[FrugalReeferJon]

Looks like Hydroids

https://www.reef2reef.com/threads/hydroids-a-reference-to-some-strategies.819522/

 

[ISpeakForTheSeas]

Myrionema sp. hydroids to be specific (either M. hargitti from the Atlantic or M. amboinense from the Pacific; I don't currently know how to differentiate the two).