coral/nem id please

[Reef Puffer]

so im pretty sure the id is a mushroom? but he crawled around the frag disk and is now situated in/under my acans. do the mushrooms sting? is he ok in there or should i be trying to get this thing out? personally i dont want him there anyway, but im not sure how to go about moving it in the first place? any help would be appreciated. thanks.