Though not universal, many dragon crabs line their shells with gaudy precious metals and stones, both for aesthetic reasons and to disguise themselves as piles of sunken treasure. Such crabs then bury themselves in loose sand and wait for unsuspecting adventurers to swim close and be ambushed. When not gem-encrusted, dragon crab shells are deep orange and grey, with patches of pale blue on the legs. They are about 60 feet in diameter, with pincers each as large as an elephant.