Because this guy moved more sand from under my larger pile of rocks than a front end loader. He axed a mithrax and gorilla crab, and forces the brittle/serpent stars out from the rocks on that side of the tank. All the brittle stars and peppermint shrimp have moved to the other pile of rocks on the opposite end of the tank and won't get near him. He's a little damn thug, that's what he is.
I have a Goby/Randal pair in quarantine and don't want to chance having them all together. So he's in my sump and I have contacted my local forum and LFS' to see if I can get him a suitable home.