Nightmare King Grimm - Art by me! : r/HollowKnight

He had a nightmare and proceeded to kill EVERYONE : r/CrusaderKings

Kirby Nightmare in Dream Land

Spoilers] Nightmare King Grimm as a Pokémon. : r/HollowKnight

DreamZzz: 71476 Zian the Cat Owl (+ Nightmare King in EU magazine) (from Brick Clicker/flo_society) : r/Legoleak

Nightmare Horror Adventures: Welcome to Crafton Mansion, Board Game

In Nightmare - Launch Trailer

Alone In The Dark On GBC Is A Bizarre Relic You Should Play At Least Once

Art] [Subclass] Pact of the Pumpkin King – A “Nightmare Before Christmas” themed subclass, complete with eldritch invocations, pact boon and new familiar : r/DnD

Little Nemo: Adventures in Slumberland (1989) - IMDb

As a hater of Slime, this TH level is a nightmare. : r/TwoDots