Help ID: tiny creature with small tentacle

[nico1997]

Hello everyone,
Today I came across a tiny (mostly white) individual on my rock. It looks like it has some small moving tentacles on its body. I tried to look at it through a microscope but it doesn’t really help me…
Have you seen that before?
Should I be worried?
At first I thought about a nudibranch but it doesn’t seem to have a proper head. I also have bristle worms, so could it be eggs or something?

Thanks

 

[EeyoreIsMySpiritAnimal]

Was it moving across the rock?

 

[nico1997]

No it wasn’t really moving on the rock, it was just barely attached to the rock.