Coriakin

Background
Coriakin was originally a star, charged by Aslan to rule the Duffers and guide them to wisdom because of past misdeeds, the exact nature of which was never known by humans (a fellow star, Ramandu, mentioned they were not for human beings to know).

During Caspian's journeys on The Dawn Treader, Coriakin appeared as a stereotypical wizard, complete with a beard and ornate robes. Quite unlike wizards, however, he always walked barefoot. He lived in a mansion that was reminiscent of English mansions on the island. Inside his mansion were items such as a spellbook and other odd items such as a Bearded Glass.

Governing the Duffers
To govern the Duffers, he required the use of magic, although they will be ruled by wisdom in the distant future. Because of the dim-witted stubbornness of his subjects, Coriakin cast a spell that merged each Duffer's two legs into 1 leg.. The Duffers, believing themselves to have been "uglified," snuck into his rooms and cast a spell to make themselves invisible, hiding their new appearance. The spell also affects Coriakin.

The Visit by the The Dawn Treader
The Duffers eventually grew tired of being invisible, and, when The Dawn Treader visited their island, coerced Lucy Pevensie into reading the spell that would make them visible again. The spell could only be read by a young girl, and the Duffers were too cowardly to send any of their own daughters. After perusing through a few other distracting spells, Lucy made all things visible in the magician's house (including Coriakin and Aslan himself).

Lucy soon saw the magician as a kind, wise fellow, hardly the terrifying sorcerer the Duffers made him out to be. He suggested that she try to convince the Duffers that their new appearance is nicer than their former one, which she succeeded in doing. The Duffers renamed themselves Monopods, but kept mixing it up with their old name and came to be known as Dufflepuds.

Dufflepuds are among the creatures that entered Aslan's Country after the final battle in Narnia.