Darkrai

Darkrai is a Dark-type Mythical Pokémon known for its ability to induce nightmares. It has a sleek, shadowy appearance with a ghostly, wisp-like body, a white ghostly plume on its head, and piercing blue eyes. Darkrai is often associated with the new moon and is known to inhabit dark, secluded areas. It is said to be able to lull people to sleep and cause them to experience vivid nightmares, though it is not inherently malevolent and often does so unintentionally.