Zhang Hongming from Chongqing, South-eastern China, has a very large and unusual birthmark that looks like a werewolf transformation!
Vascular birthmarks are not hereditary. They are thought to occur as a result of a localized imbalance in factors controlling the development and migration of skin cells. Congenital melanocytic nevus is a type of melanocytic nevus (or mole) found in infants at birth. Occurring in about 1% of infants in the United States, it is located in the area of the head and neck 15% of the time, but may occur anywhere on the body. It may appear as light brown in fair-skinned people, to almost black in darker-skinned people. Coming in a variety of sizes and appearances, they may be irregular in shape and flat, or raised and lumpy in appearance and feel.