New artifact The Never-Ending Doughnut, an unspecified-comestible base type artifact that can only be eaten when Hungry or worse, but will never get fully consumed unless the eater is a purple worm. After eating it the first time, it is perpetually “partly eaten”. You cannot become satiated by eating it.

A monster flag that designates that its inventory is actually the contents of its stomach and is therefore not stealable, nor usable by the monster. Gelatinous cubes, rock moles, and purple worms should get this flag. (Also some other proposed “eater” monsters, like the bookworm.)

If a monster (like a purple worm) eats another monster, that monster’s inventory should be added into the eater’s stomach.

Purple worms going “Burrrrp!” wake up nearby monsters.

Purple worms eat corpses in 1 turn, because they can eat the monster in 1 turn so why not the corpse?

If a shrieker summons a purple worm with its shriek, check for difficulty first. If purple worms would be out of difficulty, generate a baby purple worm instead.

Hitting a tin of long worm or purple worm meat with an undead turning beam turns it into a can of worms, which when you apply or eat it creates a bunch of random w around you. Cans of worms can also be found randomly generated.