 It has been explained elsewhere that this "heath-worm" is actually a type of snail (), or rather the black slug, "Arion ater".The girl was given a gold ring by her mother, and asked how she might best derive profit from the gold, was told to place it under a heath-worm (slug).She did so, and put it in the top of her linen chest for a few days, but then found that the little dragon had grown so large, it had broken open the chest.