What are the invisible creatures on the island of the Dufflepuds called?

The invisible creatures on the island of the Dufflepuds are called the Dufflepuds. They are introduced in The Voyage of the Dawn Treader as inhabitants who have been made invisible by the magician Coriakin.

The Dufflepuds live on an island encountered by Caspian, Edmund, Lucy, Eustace, and the crew of the Dawn Treader. They initially seem threatening because the travelers can hear and feel them without seeing them. In reality, the Dufflepuds are comic, quarrelsome creatures who want Lucy to find the spell that will restore their visibility.

Lucy eventually enters Coriakin’s house and uses a magic book to undo the invisibility enchantment. Once visible, the creatures are revealed as having a distinctive, somewhat peculiar appearance. The name Dufflepuds is also associated with “monopods,” referring to their one-legged form in descriptions of the story.

The Monopods are therefore a related descriptive term, not the best answer to this wording. “The Invisibles” and “the Duffers” are informal-sounding distractors rather than the creatures’ canonical name.