Appearance: The Bennu bird was a large imaginary bird resembling a heron. The bird may be modeled on the gray heron (Ardea cinera) or the larger Goliath heron (Ardea goliath) that lives on the coast of the Red Sea. Archaelogists have found the remains of a much larger heron that lived in the Persian Gulf area 5,000 years ago. There is some speculation that this bird may have been seen by Egyptian travelers and sparked the legend of a very large heron seen once every 500 years in Egypt.
It had a two long feathers on the crest of it's head and was often crowned with the Atef crown of Osiris (the White Crown with two ostrich plumes on either side) or with the disk of the sun.
Meaning: The Bennu was the sacred bird of Heliopolis. Bennu probably derives from the word weben, meaning "rise" or "shine." The Bennu was associated with the sun and represented the ba or soul of the sun god, Re. In the Late Period, the hieroglyph of the bird was used to represent this deity directly. As a symbol of the rising and setting sun, the Bennu was also the lord of the royal jubilee.
The Bennu was also associated with the inundation of the Nile and of the creation. Standing alone on isolated rocks of islands of high ground during the floods the heron represented the first life to appear on the primeval mound which rose from the watery chaos at the first creation. This mound was called the ben-ben. It was the Bennu bird's cry at the creation of the world that marked the beginning of time. The bennu thus was the got of time and its divisions -- hours, day, night, weeks and years.
The Bennu was also considered a manifestation of the resurrected Osiris and the bird was often shown pirched in his sacred willow tree.
The Bennu was known as the legendary phoenix to the Greeks. Herodotus, the Greek historian, says the following about the Bennu:
"Another sacred bird is the phoenix; I have not seen a phoenix myself, except in paintings, for it is very rare and only visits the country (so they say at Heliopolis) only at intervals of five hundred years, on the occasion of the death of the parent bird."
Herodotus goes on to record that the Bennu bird came from Arabia every 500 years carrying his father's body embalmed in an egg of myrrh. This Arabian bird however was said to resemble an eagle with brilliant gold and red plumage. Before the phoenix died it built a nest of incense twigs and laid down in it and died. From its body a small worm emerged that the sun's heat transformed into the new phoenix.
Another story says that the phoenix rose again from the burnt and decomposing remains of his old body and took these to Heliopolis, where he burned them.
The planet Venus was called the "star of the ship of the Bennu-Asar" (Asar is the Egyptian name of Osiris). The Bennu was also sometimes associated with Upper Egypt.