Small White Crab Came Out At Night

[Sam115]

Hello everyone, today I got a great deal on a cabbage coral and decided to also purchase the emerald crab that was under it. When I got home the crab adjusted very well, but when the lights went off in my nano I noticed a small white crab that I did not intend to purchase perched on top of my cabbage coral. I watched it for a while and he seemed fine until all of a sudden he was on one of my mushroom corals. I put him in the sump since I did not want any of my corals harm. Can someone please help me ID what kind of crab this is and declare it as reef safe or not? I have attached a picture of what this little guy looks like. He is at the top and the new emerald crab is at the bottom. Thanks!