The Green Leg Reef Hermit Crab, Paguristes sp., are a common type of reef hermit crab that is compatible with all home aquariums. These invertebrates provide an indispensible cleaner funciton to most tanks by eating degrading matter and detritus while also mixing up sandy substrates. The Green Leg Reef Hermit is named for its noticeable green legs. It is best kept in a reef style aquarium with plentiful algal buildup and other edible matter, however they will accept many other types of food.
I love the this guy. He's not shy at all, and he runs around sifting sand. My sand looks better with him stirring it around.