During Caspian X's voyage to the island, the Duffers had all turned themselves invisible to hide the fact that they each had only one leg. The Chief at the time was absolutely supported in his every decision by all the other Duffers, and he wielded much authority over them, despite the fact that he had very little authority to begin with. This Chief's daughter, Clipsie, was made responsible for reading the invisibility enchantment, only for them to end up regreting it and wishing to be made visible again. Unfortunately, the spell could only be read by a girl, and none of the Duffers wished to risk sending their own daughters, since they feared Coriakin's wrath, even though he was anything but vengeful.
When the Dawn Treader arrived, they made Lucy go into Coriakin's mansion, to read the spell.
This Chief's name remains unknown.
In the Voyage of the Dawn Treader movie, the chief appeared exactly the same as he was described in the book, with the exception that there was no mention of him having a daughter, and the reason why they sent Lucy to get the spell was because none of them could read. Though they were still afraid of Coriakin.