Well I was watching my tank and my emerald crab pops out of nowhere and starts dismantling my sun coral. It just reached its claw in there and destroyed an entire head, thankfully I was right there and picked it up. I made a frag rack out of some egg crate and suction cups, and now it's sitting safely up there with some other ones. I have never seen him go after a coral before, but I had just put this in there last night so perhaps he was confused. I know emerald crabs are opportunistic eaters, and I had been feeding garlic/pellets to try and rid what I thought was a parasite, so he hadn't been getting many meaty scraps. Just fed them their big lunch of mysis/spyro and fed my corals so hopefully he calms down or I'll have to have crablegs for dinner