Looks like a gorilla crab to me, crabs can be a bit difficult but if so bad. Hairy with claws, hum…
There are more than 4,000 species of crabs.
Mostly bad.
I have not one in any of my tanks, zero crabs.
we have two reef tanks and add different stock to both from time to time so we are not sure where it came from. we recently bought a reef from a young Dr. that had to move after med school graduation for his residency and couldn't take the livestock with him. We have been lucky and not had a lot of bad hitch hikers along the way.