A mostly-useless NetHack scroll. If non-cursed, it detects food (or the lack thereof) on the current dungeon level, revealing the type and location if there is any. If the scroll is cursed, or you are confused, it detects potions instead.

I guess you can't really go wrong with this one. Don't rely on this method for finding food; even if the scroll isn't cursed, you'll probably delay reading it until you're already fainting from lack of nutrition, and you'll pass out and get fatally gored by a mumak while you're staggering over to the yiffmelon you detected on the other side of the dungeon. A better idea is to be good and say your prayers. Personally I make it a priority to find a ring of slow digestion.