I have this I believe is a coral multiplying at a fast rate. Also they move
from one place to another, making me believe is an anemone.
I don't think is aiptasia, but I could be wrong. They are two types, one
with the base green and no coloration on tentacles, and the other one is
the opposite.
On the first pic you can see they are stretching to divide.

Any help will be appreciated.

Thanks,

Ruben

Here are the links: