Shift was a talking ape who lived near his friend/servant, Puzzle the donkey, at the base of the Great Waterfall, next to the Caldron Pool where the Great River starts its course to the sea, at the western boarder of Narnia.
He was "the cleverest, ugliest, most wrinkled Ape you can imagine", and was perhaps the most imfamous con-artist the World of Narnia had ever seen.
Nothing is known of Shift's history before he and Puzzle discovered a lion's skin in the Great Waterfall. He was so old that no one remembered when he came to live there.
Shift's greed served as his primary motivation. His actions to satisfy his greed increased his vileness over time. From lying to his "friend" Puzzle, he moved to manipulating the other talking animals of Narnia. In the end he had no problem murdering them and selling them into slavery to increase his own wealth and power.
As Shift's actions became increasingly evil, he also became increasingly human in his appearance and in the way he presented himself. He donned human clothing and explained that he was not an ape, and that if he appeared as one, it was only because he was "so very old: hundreds and hundreds of years old."
Shift gained the power to pursue these actions by tricking Puzzle into impersonating Aslan, the true ruler of Narnia, using his claimed humanity as 'evidence' of his great wisdom to justify how he was the only one who could speak to Aslan. Later, to secure the assistance of the neighboring country Calorman, he insisted that their god Tash and Aslan were one of the same.
Although one of the leaders of the conspiracy when it began, over time Shift turned to drink and was known to spend more time enjoying his ill-gotten goods rather than actually doing any work, with the Calormens using him more as a figurehead than anything else due to his established connection with 'Tashlan'.
Shift met his end when he was thrown into the stable by Tirian, where Tash ate him.
- See also: The Last Battle: Plot summary