Photo scanned from The Ultimate Encyclopedia of Mythology by Arthur Cotterell and Rachel Storm (2002, Select Editions): In Egyptian mythology, Ra is the falcon-headed sun god wearing the disc of the sun on his head.

Zoomorphism
Egyptian divinities are often illustrated as part-human and part-animal beings. The reason behind these zoomorphic deities has long been explained by mythologists.

Since ancient Egypt was surrounded by a hostile desert landscape, its inhabitants—humans and animals alike—depended on the great rivers that provided water and fertile soil. As they had to share the fertile flood plain of the Nile with these dangerous animals, the ancient Egyptians learned to fear and respect them, giving rise to animal cults which graduated into the worship of deities with animal characteristics.