Old Uighur Turkish is a period in which the first works of Turkish language and literature were given. It is known that many studies were translated into Turkish during this era beacuse Budism and Maniheism were adopted as a new religion. Although some original works were written, this era was a period of translation. These studies contain many examples of tales, stories and epics owing to the the fact that Budism expressed its teaching by such narration. Numerous examples of metamorphosis are found in the these works which are known as Jakata and Avadana. In this study, the examples of metamorphosis, the reasons for metamorphosis, who exacuted the metamorphosis, the metamorphosis process and the results of metamorphosis in Jataka and Avadana will be studied.