Dying while turning to slime (but not dying BY turning to slime) leaves behind a large glob of green slime instead of a corpse in your bones file.
When you are sufficiently far along in the process of turning to slime (no more than a few turns away from converting completely), barehanded and barefooted attacks you make will be treated as sliming attacks and will turn enemies to slime as if you are already a green slime.
The ring of warning, and only that, should indicate the exact amount of turns you have left to live when afflicted by a timed instadeath such as sliming, stoning, or strangulation. (And drowning and other forms of suffocation in variants that have that.) This feedback is conveyed by the ring vibrating that number of times, e.g. “Your [ring] vibrates twice.” Possibly it should only happen when the amount of turns to live is low because it doesn’t make that much sense for it to vibrate 20 times in one turn and have the hero count that accurately.
Handling a cursed glob of green slime (picking it up, throwing it, etc) makes it start to slime you, using itself up in the process.
Green slimes have an engulfing attack that guarantees to start the sliming process (assuming the player isn’t unchanging, on fire, etc).
You can somehow weaponize globs of green slime to forcibly transform other monsters into slime. Possibly this could be as simple as throwing or flinging the globs at them, perhaps subject to a monster magic resistance check for the transformation to work.
When you are turning to slime, higher luck increases the odds of a container trap or magic trap being a tower of flame, and increases rather than decreases the odds of any tower of flame trap (container, magic and fire) hitting you.
Unchanging prevents you from starting to turn to stone (it already prevents starting to turn to slime), and if you are in the process of turning to either, it halts the process but does not cure it.
New monster: green cube, which combines the abilities of a green slime and gelatinous cube: both sliming and paralysis.
