Species: peryton
A peryton is a legendary predatory deer/bird hybrid. It's said to have the head, neck, antlers, and forelegs of a stag and the feathers, wings, and hindquarters of a large bird. Other interpretations of its appearance also appear, including a stag with bird wings.
Curiously, perytons also possessed a human-shaped shadow. After a peryton killed a human, their principle prey, and bathed in his/her blood, the shadow would return to a normal shape. Perytons could only kill one human before being rendered harmless. Human weapons allegedly had no effect on a peryton.