Polyp's cropping up.....friends or foes?
 

My 150 gallon tank has been up for a year now, and in the past few months i have had several (about a dozen actually) of these polyp's appear on some live rock. The coral I presently have are:

Monti
Bird's Nest
Hydnophora-Horn Coral
Digitata
Zoanthid Button Polyp
Pink Button Polyp - Zoa
Red Open Brain
Acan Lord
Australian Acan
Clove Polyp
Chalice

Can these polyps potentialy harm these or any coral and should they be removed?

Many thanks.

looks look a green button polyp to me. No more dangerious then most palys. they do have a slight sting that can harm some sps.

Those look like protopalythoas to me? Some live in colonies and some seem to cruise around on their own and pop up here and there.

looks like palys to me.