Sinistea
Ghost types are clearly where the writers have their fun. Sinistea, part of Sword and Shield’s deeply peculiar divergence into a whole Beauty & the Beast fan-fiction, got some odd entries for that game. We learned that it forms when “a lonely spirit possessed a cold, leftover cup of tea.” It was added, “It absorbs the life-force of those who drink it. It waits patiently, but opportunities are fleeting—it tastes so bad that it gets spat out immediately.”
But Scarlet removes any generous ambiguity left by the previous game:
The soul of someone who died alone possessed some leftover tea. This Pokémon appears in hotels and houses.
Then Violet, noticing you reeling from the news that it’s a dead person, throws down with:
Sinistea gets into your body when you drink it, and then it steals your vitality from within. It also tastes awful.
