According to ancient Egyptian myth, the Bennu had created itself from a fire that was burned on a holy tree in one of the sacred precincts of the temple of Ra. Other versions say that the Bennu bird burst forth from the heart of Osiris. The Bennu was supposed to have rested on a sacred pillar that was known as the benben-stone. The Egyptian priests showed this pillar to visitors, who considered it the most holy place on earth.
The Bennu was pictured as a grey, purple, blue, or white heron with a long beak and a two-feathered crest. Occasionally the Bennu was depicted as a yellow wagtail, or as an eagle with feathers of red and gold. In rare instances the Bennu was pictured as a man with the head of a heron, wearing a white or blue mummy dress under a transparent long coat. The Bennu was considered the “soul” of the god Atum, Ra, or Osiris.
A large species of heron, nowadays extinct, occurred on the Arabian Peninsula in comparatively recent times; it may have been the ultimate inspiration for the Bennu. Reflecting this, the species was described as Bennu Heron (Ardea bennuides).