Coriakin

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 their misdeeds is unclear (a fellow star, Ramandu, mentions they are not for human beings to know).

In The Voyage of the Dawn Treader, Coriakin appears as a stereotypical wizard, complete with a beard and ornate robes. He lives in a mansion reminiscent of English mansions on the island. He has a spellbook kept in a room on the top floor. He owns various other odd items such as a Bearded Glass.

He requires magic to govern the Duffers, although they will be ruled by wisdom in the distant future. Because of the dim-witted stubbornness of his subjects, Coriakin eventually casts a spell that merges their legs into a single leg each. The Duffers, believing themselves to have been "uglified," sneak into his rooms and cast a spell to make themselves invisible, hiding their new appearance. The spell also affects Coriakin. However, the Duffers eventually tire of this, and coerce Lucy Pevensie into reading the spell that makes 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 sees the magician as a kind, wise fellow, hardly the terrifying sorcerer the Duffers made him out to be. He suggests that she try to convince the Duffers that their new appearance is nicer than their former one, which she succeeds in doing. The dwarfs rename themselves Monopods, but keep mixing it up with their old name and come to be known as Dufflepuds.

Dufflepuds are among the creatures that entered Aslan's Country in The Last Battle. Presumably Coriakin's efforts at enlightening them are successful by that time.