Help Identifying thing on rock

[THEBOOM1011]

Hi so I'm not able to correctly take a photo of it for 2 reasons, I'm not good at photography especially with water and its in an awkward position towards the back of the tank but I'll try my best to explain it and if need be try my best to take a viewable photo.
So it kinda looks like a closed zoanthid but I have never seen it open and it is multiplying on the rock, I don't think its a sponge doesn't have some features could be wrong, it looks harmless but I'd rather be safe than sorry, the rock that its on isnt live rock it was dry live rock so idk where it came from I can be wrong since the rock was from a used tank but was left out of water for a few days. I also dont have any corals currently. So if you can help that'd be much appreciated.

 

[fishguy242]

a pic would really help

 

[MERKEY]

With what you have described and not having a picture I would say sponge.

 

[SliceGolfer]

Most common things could be a pineapple sponge, Aiptasia, vermetid snail, algae, clump of food

 

[SHNICI]

it's looking like zoas, close, multiplying? All this there sound like tunicate (check the link), or sponges.