They believed Coriakin to be a tyrant, when in fact he tried to educate the Dufflepuds, and helped them survive.
The duffers worked for Coriakin for many generations; how many is not known. Their constant foolishness led them to rebel against him for trying to help them. As punishment, they were made into monopods. Later, however, they grew to hate their new appearance so deeply that they used Coriakin's magic to make themselves invisible.
In 2303 NY, they kidnapped a party of Narnian visitors, and forced Queen Lucy of Narnia to undo the invisibility spell, which they had come to dislike. At that time it was declared by Aslan that they were not yet ready to see him. It is possible that they eventually were ready and were able to meet with him.
Later, Reepicheep taught the Duffers how to use their large feet as sort of a small raft or boat, and he even taught them how to fashion crude paddles to help them steer themselves in the water. They even paddled out as the Dawn Treader and its crew sailed out of sight.
The duffers were loyal to one another, and especially to their leader, whom they loudly and constantly supported with many voices of full-hearted agreement. In fact, he rarely managed to say more than six or seven words without being interrupted by their encouragements and agreements.
The dufflepuds were somewhat cowardly, quite foolish, and very full of themselves, but they were not bad-natured people. They were most like simple children in character. They possessed infallible logic, and concluded (among many other profound statements) that water is "powerful wet stuff".
The dufflepuds were originally common dwarfs called Duffers, and were said to be rather plain creatures. They were later transformed into Monopods by Coriakin as punishment for disobedience. In this form, each had only one leg, right under its body, and a huge foot the size of a small coracle.
Although almost everyone else liked the change, the duffers were so ashamed of their new, "uglified" form that they snuck into the magician's library and used his magic book to turn themselves invisible.
By the time Caspian and his crew reached the island, the fickle duffers had become "mortal tired of being invisible," but they were too afraid to sneak upstairs and use the magician's book again, so they threatened the travelers with death unless Lucy would do it for them (only the magician or a little girl can say the spell).
She succeeded, and, as far as we know, they remained visible Monopods for the rest of their lives.
The name Dufflepud is a garbled combination of Duffer and Monopod. They combined their old name of Duffers (given by Coriakin) with the new name of Monopods (given by the visitors) to create their final name of "Dufflepuds." Not being able to pronounce "Monopod" properly, they also called themselves Money-puds, Pomonods, and Poddymons, before settling on Dufflepuds.
- A Dufflepud's single foot is so large it can be used as an umbrella when he is on his back, or can be used as a canoe if the Dufflepud goes on water.