Acid Ducks
A species of small waterfowl native to the Black Hills area of Varys. Acid Ducks are hardy birds that are capable of digesting a wide variety of foods - including weeds, insects, small fish, carrion and various species of plants that would be poisonous to most other creatures. Their dense plumage is coated will an oily substance secreted by a gland above their beak which not only helps to waterproof them, but is also remarkably resistant to acidic corrosion.
Acid Ducks are fairly numerous in the Black Hills, making them an important source of nutrition for any settlement there. Unfortunately their rather unsavoury diet and the adaptations they have made to survive in this hostile environment make their flesh tough and lend them a sour and acidic taste. As well as being hunted for food, Acid Duck oil glands are sometimes harvested in order to help mix special coatings that make wood or leather more resistant to the harsh conditions of the area.