All info is from Reef'd Up Aquaticspossibly Polydectus cupulifer: Not Reef Safe
This is another example of a Xanthid crab, and this is one crab that frequently falls under the common name,
“Teddy Bear Crab.” It is also frequently called a “Gorilla Crab”. As these names are common names though they also fall onto several other types of crabs. See the following website for more details/warnings on Xanthid crabs.
Invertebrates: Crustaceans (Crabs) Part II » Reef'd Up Aquatics
here is another look at it...