ID please

[Raamiah]

These guys showed up on my purple deaths. Not sure how they got in as I dipped everything but they're here and now they're spreading. I thought it was an algae but just today I saw them holding onto fish food from the large top part. Any ideas? I can't find anything from hitchhiker ID sheets or searches online. Any ideas on getting rid of them too? They seem to b making my zoas unhappy.

 

[Skimmy]

hydroids... bad... and some can sting even you...
remove with heavy plastic brush, like a plastic paint stripper brush from home despot
maybe wear gloves when removing