Crab identification please

[Robb1821i]

Found this hitchhiker and not sure if he's cleaning my acro or hurting it.

 

[lelandmarine]

Maybe I’m blind or you have a camouflage crab but I can’t see anything

 

[Robb1821i]

Maybe I’m blind or you have a camouflage crab but I can’t see anything

 

[TriggerFinger]

It doesn’t look like something I would want on my acros...

 

[Gtinnel]

I can't help with what kind of crab it is but IME most crabs are bad. I'd be especially worried if it liked hanging out near my corals

 

[Robb1821i]

I can't help with what kind of crab it is but IME most crabs are bad. I'd be especially worried if it liked hanging out near my corals

That's my experience so far but I don't see him grabbing polyps, think he might get getting dried mucus.
I had an emerald that ended up being an acro eater

 

[Gtinnel]

I had an emerald that ended up being an acro eater

I had an emerald that was a saint for over one year and when I got rid of my algea problems he decided he like soft corals. Im guessing he got hungry. Mine at least had a taste for cheap corals.

 

[Robb1821i]

Anybody out there know what it is?
Moderator, just realized this should in hitchhiker and critter id.