Eating a bat should have a 1% chance of killing you.
Oh , we need
some kind of Corona reference in 0.59, no doubt.
Outright killing the player "of a rare Asian virus" would be the easiest, or we could make a whole new disease. Coughing sound effect, chest/head damage, occasional unconsciousness...
How about "bat soup" as a material type and the player refusing to drink
it with a message like "you hesistate, recalling tales of a ravaged land far across the sea." Naturally it should belong to Scabies...
EDIT: Also, bottomless pits
Treated as an unwalkable tile like ocean. Get knocked backwards into one, or have your Levitation run out while floating over it, and " (Player) fell into an endless void".
EDIT 2: "Booby trapped" chests
On an unsuccessful Dex check (Luck save to avoid?) player is hit for damage. Successful check means the chest is opened as usual, and a dagger is guaranteed to be found within. For extra Fun, make it a chance of a poisoned dagger.