Sorry I tried to do a quick search but want to ID this guy before he crawls back into his hole and I can't get him out if needed. My first time with live rock and after 4 weeks of seeing nothing but two asterina starfish this bad boy pops out. I assume he is some sort of crab but his shell seems super soft almost like soft coral against the rock. He has several black legs or tentacles. Any idea what he is? Nothing else in the tank yet, it is cycled but haven't added a fish yet.