There once was a fisherman who sold all of his catches to the King. One day, the fisherman caught a golden crab, which he set aside instead of selling it to the King. Much to the surprise of the fisherman and his wife, the golden crab could talk! He requested that the fisherman go to the King and tell him that he wished to marry his youngest daughter. The fisherman delivered this wish to the King, who realized that the golden grab was likely an enchanted prince, so he set the golden crab to a few tasks to prove himself. The golden grab succeeded in all the tasks, yet remained a crab, but the King allowed him to marry his daughter anyway. The golden crab turned into a prince each night, but back into a crab everyday -- a secret which his young wife kept until the King tried to find her a new, human husband. When the princess speaks the truth, her golden crab prince disappears. Then it falls to the fisherman once again to reunite the young couple.
Andrew Lang (1844-1912) was a Scottish writer who collected fairy and folk tales from various cultures and put them together in twelve volumes of tales. He was noted for taking the tales from as many original sources as possible, keeping the fairy tales close to their intended meanings.