Can anybody please ID those ?

[bok]

Hi!
After a few months of establishing my aquarium, I am still finding new hitchhikers.
What is this ? It is located right underneath of my neon green Caulastreea .
Is soft, and the opening is moving in the flow. After I stop the flow, it is still moving like a pulsating membrane

A close-up :

 

[bok]

And also , on a side of an old rock , just found these small ...somethings.
What are these ??

 

[DallasNYC]

The first picture looks like it has lots of 'mouths' around the perimeter which makes me think it might be some kind of sponge with its many inlet and outlets. But I've never seen a sponge move?

The second picture looks like maybe Ball Anemones

 

[Bongo Shrimp]

The first is of a colonial tunicate. They will open and close and do some funky stuff as they grow and feed. The second one is probably a hidden cup coral. Just a little LPS type guy. Not a nem cause it looks to have a skeleton.