Part of my front tooth flaked off and its all raw and sensitive.
Here are things I like:
PCs who are children or teenagers who rescue other children or teenagers or fail horribly trying to rescue them. For tactical reasons and emotional and spiritual ones. (Monsterhearts. Over the Garden Wall. Adventure Time. John Bellairs. Gorey. Shintaro Kago. Takato Yamamoto. Maruo)
Wizards are from some wizard academy and they are all hot, condescending rich kids that don't really give you the time of day. like this one.
Dopplegangers not so much in the D&D monster sense, but in the literal sense. Jealous alternates. And places that are dopplegangers. (If a PC dies when no one is around, ask the player in secret if they want to come back as the malignant, weird version of themselves. They weep after killing a monster. When they think no one is looking, their character stares into the distance and they detect as neither evil nor good, but they are terrified of _sanctuary_. And they gain a fetish for masks of any kind, always wear them.).
Animals that wear clothes and act like people but also eat one another and don't really understand language and just pretend at civilization and stare too long at the humans that talk to them. (there is a 1 in 3 chance that any village or town is animals instead of people. The shops take nuts (squirrels sell books and clothing and rations and tools) or worms (birds sell spells and secrets) or fresh meat (weapons, armor) instead of money, the courts determine things with fights to the death using only claws and teeth (you can probably convince the judge that a sword or something is like "your claws" if you do a good job of miming. otherwise charisma check or something))
People riding deer that seem to understand them like a person would.
Fairytales and Ovid and things where people are punished because the world is unfair and because they weren't clever and hadn't figured out the secrets. (dryads trapped in trees by thug boyfriends. nice people turned into monsters because the mayor didn't like them. children raised as killers because their parents are awful. the emperor is the worst of all, like a monster pope.)
Gods that are monster.
Goblins that are just the lost boys and their king is a scaly peter pan. They are at war for esoteric reasons with other goblins led by the serious and kind Wendy (who is an Alice). They have magical scarves made by mothers they've forgotten (cantrip 1/game and then the scarf is ruined, the scales fall off and the boy or girl starts growing into an adult).
Magical longjongs (always warm or jump high or better AC).
Landscapes that are the maps of people's minds. Like Ghostland. Or the limbic crust in Limbo.
Things with eyes like flashlights. Like that frog in the fiend folio.
Ghouls that glow like ghosts in the night.