 Cuélebre

Cuélebre (Asturian) or Culebre (Cantabrian), is a giant winged serpent-dragon of the Asturian and Cantabrian mythology, that lives in a cave, guards treasures and keeps "anjanas" (also known as "xanas") as prisoners.Although they are immortal, the cuélebre age, and their scales become thick and impenetrable, and bat wings grow in their bodies.