Not an easy one..

[tezaman]

its there about a month , it was way smaller , now its starts to multiply the heads , and they got a shape too.
what is this , some kind of egg, or coral?

 

[tydeck]

Vertimid snail. Pest.

 

[ISpeakForTheSeas]

Is the white tube connected to the little pile there? If so, it reminds me of the thread below, and is likely a tunicate (or sponge) of some kind. Those little eggs/heads in the pile may actually be eggs or new tunicates/sponges budding up.

What are these? Cannot figure it out. Hitchhiker ID

Small roundish soft thing sitting on a “nest” of tentacles similar to that of a nudibranch or bubble tip anemone, however they do not move freely and are stationed where they are, have not moved an inch in almost a week. I think Nudibranch is ruled out When I touch them they react and “extend”...

www.reef2reef.com

 

[tezaman]

Not a Vermit snail.

Let me put some more clue's

 

[ISpeakForTheSeas]

Yeah, that looks like a tunicate of some kind to me (though I couldn't tell you if the "eggs" as the base are actually eggs - sexual reproduction - or buds - asexual reproduction). So, yeah, very similar to the one in the link I shared above (though almost certainly a different species).

Edit: to add, tunicates are generally harmless filter feeders, and yours don't look like the invasive kind, so I'd say to keep them/don't worry about them.

 

[EeyoreIsMySpiritAnimal]

Not a Vermit snail.

Let me put some more clue's

Very cool!