Black bug looking thing stressing mushroom ? Pros only plzz

[frizzayyyyreef]

So tonight after lights out I tried feeding my mushroom who just had a baby after 2 years but always had this slime coming off it ...now tonight I noticed a black bug idk if it’s the amiphode things however you spell it but it came out of the rock took a piece of shrimp and darted right back in there’s no way I can get a pic but I wonder it seems like below the mushroom is his home can it be the reason for slime ?!

 

[JGT]

Need pics. Sounds too big for amphipod.

 

[WheatToast]

I am not the best pro, but here are some images you could use to identify.
Copepod
Amphipod
Munnid isopod

These all tend to be harmless in most aquariums (they graze on algae/detritus while larger organisms enjoy feeding on them). I have heard that amphipods might eat dying corals though (and healthy corals VERY VERY VERY RARELY).

Need pics. Sounds too big for amphipod.

Should be pictures under white lighting (using a flashlight, perhaps). Maybe you can lure the "bug" out with sinking pellets to take a photo.