The Tavern

If you quaff a potion of gas:

1) You "make noises". "Brrrrrp." "Pfffut." "Pffff-- whoops."
2) You gain an ability, "Let loose!" It releases a Mephitic Cloud centered on the caster.
3) Like a ring of teleportation, sometimes your ability goes off on its own. "Who... me?"

This sort of suggestion is exactly what CYC is for.

I was being serious ... it would be a funnier and more interesting feature than scroll of random uselessness is presently. (Actually there MIGHT be a time when that has an effect, I think... when you get the butterflies and the next unidented scroll you read is immolation. But I haven't tested that!)

replacement for potion of degeneration: potion of ass. polymorphs you into donkey form, which can't read scrolls, but has level 10 of the hooves mutation. if you quaff a potion of ass while in statue form, you destroy the floor every turn, falling into the next level, and any attacks against 'w' glyph monsters are one-hit kills

another great idea is to replace potion of poison with potion of glass, which works like scroll of paper

I once had my life saved by a scroll of random uselessness.