Puzzle was a talking donkey, and his name suited him very well. He was rather dense, but he had a good heart and did what was right in the end.
He was a friend of Shift, who was a conniving ape that abused Puzzle's trust for his own gain. Puzzle was often tricked into doing whatever Shift told him to do, even if he knew it was wrong.
Puzzle was rescued by Jill Pole, and saw the error of his ways. Jill protected Puzzle from Tirian when he wanted to kill him for pretending to be Aslan. He joins the group of good Narnians in the Last Battle of Narnia.
When the real Aslan arrived in Narnia, he had some private words with Puzzle that made his ears go down, and some more words that made his ears go up. After this private discussion, he was officially pardoned and led into Aslan's Country.