Volo's Guide to Assorted
Demiplanes of Interest
Burger Kingdom:
The realm of King Burgermeister. Milkshake lakes, hamburger trees, talking door knockers. It's all very odd.
Elemental Plane of Booze
Elemental Plane consisting of booze. Less crudely known as the Elemental Plane of Spirits, but let's not kid ourselves.
Inhabitants of Booze
Not Me! (small booze elemental): Mischievous prankster from the Elemental Plane of Booze. His name does actually end in an exclamation point, yes.
Elemental Plane of Candy
You get the idea here.
Inhabitants of Candy
The Lollipop Dragon (adult green dragon): Dragon who lives in the Lollipop Forest on the Elemental Plane of Candy.
Lost Plane of Pun-Pun
The legendary kobold homeworld. The last survivors optimized themselves completely out of existance.
Inhabitants of Pun-Pun
Gary (kobold ardent-1 with nigh-infinite power): An ancient, long dead kobold, who optimized himself, but not nearly as much as other natives of Pun-Pun. His final fate is unclear.
Pun-Pun (kobolds of infinite power): The natives of the kobold homeplane of Pun-Pun, who optimized themselves to near infinity. Unfortunately, their kobold bodies could not house this power, so they exist now only as disembodied voices with no means to utilize their power. They're universally bored.
Plane of Faerie (Hey, actual WotC plane; property of Wotc)
Inhabitatns of Faerie
The Cowardly Illithid (mind flayer): A mind flayer living in the Plane of Faerie. He's terrified of everything, but he has a nice singing voice.
The Wicked Night Hag of the Deep South (Night Hag): Nemesis of Fae the Fairy Princess, and eater of children, getter of pretties and little dogs, too, and bicycling enthusiast. She's very fond of gingerbread.