Bonneter

The Bonneters are a race of hat-like beings found in the region of Bonneton within the Cap Kingdom of Super Mario Odyssey. They all have Eerie-like bodies, heads shaped like hats, and big eyes with irises of various colors. As demonstrated by Cappy, they can also take on the appearances of other hats, such as the Mario Cap, and capture other beings, both animate or inanimate. Male Bonneters have top hat-shaped heads with a more pronounced eyebrow ridge while female Bonneters have cloche hat-shaped heads with ribbons and wingtip eyelashes.

There are two recurring post-game quests involving Bonneters after the player defeats Bowser in the Moon Kingdom:
 * The first quest appears in the Sand Kingdom, Metro Kingdom, Snow Kingdom, Luncheon Kingdom, and Mushroom Kingdom, and is called "Hat-and-Seek". This quest has the player looking for Bonneters who take the form of other people's hats, similar to Cappy. Talking to that person with the Bonneter in it will award the player with a Power Moon.
 * The second quest involves a Bonneter biologist who appears in the Wooded Kingdom, Lost Kingdom, Snow Kingdom, and Bowser's Kingdom, and will require the player to approach it while capturing an Uproot, Tropical Wiggler, Snow Cheep Cheep, and Pokio respectively to gain a Power Moon.

Trivia

 * The Bonneters resemble and share similarities to tsukumogami, a type of youkai from Japanese folklore.