Please ID?

[leaf2reef]

Hello,
I am new to reef2reef and to the reef hobby in general.
Recently, I bought an Acan frag and noticed a small bubbly extension in it.
Is it part of the Acan or is it a pest I should be concerned about?
In my tank it is now more of a purple brownish color, not as colorful as the picture posted from the seller yet.
Thanks

 

[blaxsun]

Looks like a bounce mushroom (possibly a St. Thomas).

 

[leaf2reef]

I thought, It maybe a bounce mushroom but I was not sure that they could coexist that close to each other!
Thanks