The phoenix, or fire bird, has been a part of the mythology of most
ancient cultures in the Eastern Hemisphere. It is a universal symbol of
rebirth and regeneration. Its most recent incarnation came to us as the
cherished pet of Albus Dumbledore in the Harry Potter book and movie

Phoenix Rising (Public Domain Image)Phoenix Rising (Public Domain Image)

The bird was known to be beautiful and have an extravagant display of colorful plumage of gold and scarlet. In some traditions of the story the colors may vary with selections of green, purple, and blue feathers. After a glorious life span which can range from five to ten centuries, as it nears the end of its life, the bird builds itself a nest of twigs which spontaneously combusts, consuming both nest and bird. From the remaining ashes an egg or young bird rises, ready to live again. 

In some myths, the new bird embalms the old ashes in an egg made of myrrh and deposits it in the Egyptian city of Heliopolis. In some myths, the rising from the ashes is indicative of the phoenix being immortal, while in others it is indicative of the new phoenix being the child of the previous bird.

The cry of the phoenix is supposed to be a beautiful song.

Source: Wikipedia