Quotation from: The Notebooks of Leonardo Da Vinci

Written by: Leonardo da Vinci

You know that you cannot invent animals without limbs, each of
which, in itself, must resemble those of some other animal. Hence if
you wish to make an animal, imagined by you, appear natural--let us
say a Dragon, take for its head that of a mastiff or hound, with the
eyes of a cat, the ears of a porcupine, the nose of a greyhound, the
brow of a lion, the temples of an old cock, the neck of a water
tortoise.