A race where you start polymorphed into a low level monster and with every level you gain, you can polymorph into a stronger monster.

Slaughterhouses as a Gehennom special room, filled with corpses, leashes, and knives.

Change the message “This food tastes okay.” for “palatable” food to “This food tastes gamey.”

Change the “killed by the wrath of [god]” death to “annihilated”.

Make death messages more diverse and flavorful. Base it on the attack type of the monster and possibly the weapon used, so that “killed by a jackal” becomes “clawed/mauled/shredded by a jackal”, “killed by a gnome” becomes “bludgeoned to death by a gnome” if it was wielding an aklys, “stabbed to death by a gnome” if it was wielding a dagger, etc.

Note that this creates a headache for tournaments that track unique deaths.

Kicking a sink may produce an air elemental.