In the Egyptian Book of the Dead, several chapters are devoted to the making of transformations into several forms. These transformations are all done in the realm of the dead, and are meant to help the deceased make his journey through the realms of the dead into the Kingdom of Osiris.
Each chapter presented here is in itself a formulae for transformation, which through recital in the realms of the dead allowed transformation to take place. Chapters in the Theban Recension have no fixed order, and selection of chapters seems often left to the purchaser or scribe.
There are few stories of making transformations in the realms of the living. Most shifting was for the object of making perfect the soul in the Dead-lands.
The first chapter (ch86) is on making the transformation into a Swallow. The swallow represented an incarnation of Serquet, the Scorpion-goddess, daughter of Isis and Ra, and a harbinger of glad tidings. All roads are then known to him, the deceased, and he flies everywhere in sunshine, and is not doomed to remain in the Dead-land.
The next chapter (ch77) is on making the transformation into a Hawk of Gold. The Hawk was a giant, measuring 4 cubits from wing tip to wing tip. The reason for this form was to fly up into the sky to the realm of the Sun-God, so he could refresh himself with the offerings recieved by the gods. Once there, he could transform himself into a Spirit-soul and live with the Spirit-souls of Osiris and Ra.
The next chapter (ch78) is a very important and long one in the Book of the Dead. It is the chapter of making the transformation into the God-hawk. This recital means to make the deceased into the very hawk which is Horus, son of Osiris and Isis. Horus [the elder] was believed to have provided the primeval Spirit-soul with a Spirit-body, and is therefore linked with Tem, who dwelt in the Celestial Waters, before there were "gods" or men. Horus, son of Osiris and Isis, was a vessel for this primeval Spirit-soul, and by making the tranformation into the God-hawk, one was part of the being and substance of God, and a fellow with Osiris, Horus, and Ra, their equal.
This chapter (ch87) is on making the transformation into the serpent Sata. The serpent could cast off its old skin, and appear with a new one, and so is integral to reincarnation/immortality myth. By becoming the serpent Sata, one would be associated with new birth and a rejuvenated body.
The next chapter (ch88) is on making the transformation into a crocodile. With this body, one could strike terror that is always associated with the crocodile. One could then traverse the Nile(integral to Egyptian myth), or any stream without danger. [along the Blue Nile, until recently, not sure about now, there were myths that natives could tranform into crocodiles at will]
This chapter (ch82) is on the transformation into the god Ptah. This god is highly regarded as one of the cosmic Gods, who made the heavens and the earth at the command of Thoth. This tranformation guaranteed the strength of Ptah, a master blacksmith, and a portion of his offerings, and he could identify himself with Tem and Ra.
The next recital (ch85) is of making the transformation into the soul of Temu [Tem]. This chapter was very important, as it made one into the Soul-God of Nu [the heavens], and is the counterpart of the primeval Soul of Temu, the Father of the Gods, placed in Ra, which exists under the name Khepera. In this form, the deceased becomes an emanation of the Light-God.
This chapter (ch83) is for making the transformation into the Benu bird. This bird, which is sometimes identified with thh Phoenix, is self-produced, and therefore a extension of the god Khepera, who was self produced and self-begotten. This form has many functions, including alowing the deceased to take any form he pleases, to travel over the earth with Ra, to eat the food that Osiris eats, and to be free from every evil thing forever.
This chapter (ch84) is on making transformation into a Heron. The purpose of this transformation is vague. It is thought that by taking this form, one gains power over the animals of the sacrifice, and could then provide himself with food and offerings. It is also thought that one could never take the form of the Heron unless one was pure in thought and deed, part of the recital is this proclamation.
The next chapter (ch81a) is on making the transformation into a Lotus flower. This flower was a favourite of Ra, and is an emanation of him, and represents of idea of resurrection, to emerge daily into heaven like the Sun-god. The lotus is also a representation of Nefer-Tem [young Tem], son of Ptah and Sekhmet. In this way, one becomes both the elder and juvenile forms of the same god. This is also seen with Horus.
The final chapter (ch80) in this version of the Book of the Dead which concerns transformation is on becoming the God who Giveth Light in the Darkness. The land of the dead was believed to contain many dark places before one finally reached the Kingdom of Osiris. To take this form one could produce light and so travel in safety. In this form, one was a personification of Horus, and of Set, and could emit light and dark at his whim. The deceased could merge his form with the substance of Osiris, the Moon-god, just as earlier he could merge himself with the dual-soul of Temu.
-- Budge, Sir E. A. Wallis, ed. and tr. The Book of the Dead. Random House, 1995.