What are these hitchhikers?

[charred salad]

here they are:

^full tank shot =]

^Brownish tentacle things...idk what they are. i dont think they are aptasia though... (centered)

^coral thing...what is it? (centered)

 

[charred salad]

i know the last pic looks like a shell...but its not: its pink in color and it opens and closes and moves.

 

[yosemite sam]

The first thing looks like a type of brittle star. It may be a 'mini' brittle, which is a common hitchhiker.
I'm not sure what the second thing is. When you say it moves, do you mean it roams around the tank?

 

[charred salad]

i mean it kinda sways...it may be due to the water flow but it contracts and retracts.