A
dubious NetHack scroll that does what it says it does (which is not very useful, in my opinion). It will tame every
monster within one square of you, i.e. they become your
pets.
Apparently, a scroll of taming will also calm down an angry shopkeeper, provided he's right next to you. In just the right circumstances (such as when an angry shopkeeper is beating you to death), I suppose this could prove useful.
Guess what the cursed version does...