A diminutive (less than 1 inch wide) soft-shell crab that makes its home inside an oyster and lives off the food its host eats. Oyster crabs are certainly not found in all oysters, and most oyster processing plants don't bother to collect them during shucking so the supply is very limited. They're best prepared simply sautéed in butter. Gourmets consider these pale-pink crustaceans a delicacy.