In this parallel timeline, the Mage was a talented young sorcerer from Agrabah, who was the apprentice of Jafar and studied magic under him at the Royal Palace. It was together that he and his Master originally acquired the Genie's Lamp, and it was he who first used its power. However, the wish he was directed to make by Jafar, intended to protect Agrabah from its military enemies, led to much death which drove the Mage to insane levels of guilt and to the decision to go hide the Lamp where Jafar could never find it (nor any other man).
With the help of a sympathetic Royal Guard, and of an ancient Scarab Staff and scrolls, he located the Cave of Wonders, planning to seal the Lamp into the Cave and then burn the scrolls which had allowed the Cave to be found. Before they could finish doing so, they were met with Jafar and his fellow warlock Iago; in the ensuing battle, the Royal Guard died (his soul becoming that animating the gate of the Cave), Iago was transformed into a parrot, and the Mage himself was transformed into a Magic Carpet who was sealed inside the Cave himself.
Behind the scenes
This version of the Magic Carpet appears in the 2015 tribute comic Diamond in the Rough, written by Theo Dolev and illustrated by Ophir Sheriff. Despite some minor differences in circumstances, it is Diamond in the Rough’s intent that it serve as a loose prequel to the events of Aladdin, though of no other entry in the Aladdin series; as such, it can be assumed that the Diamond Universe the Magic Carpet's later fate, beyond what is shown in the comic, matches up to the actions of his Prime Universe counterpart in the movie.