Staghorn Hermit Crab - Reef Safe?

[kbayashi]

I just got a Staghorn Hermit Crab and within the first two days he/she ate three Turbo Snails. That’s what the store called him, but I’m not positive on his name. He has a shell that is similar to coral but the store said that they wouldn’t change shells. Is this even a hermit? And even though it's a new tank (just LR & damsels), is he aggressive?
Thanks in advance.

 

[joe's reefer]

i dont thin they are they are good for small aggressive tanks