Wait!

Wait! is the beginning of several messages relating to attempting to walk where a previously unnoticed monster is hiding. These include:
 * Wait! That's a foo! - for mimics (and the Wizard of Yendor's clone after using Double Trouble)
 * Wait! There's a foo hiding under ! - for spiders, snakes, and other monsters capable of hiding under items
 * Also seen as Wait! There's a hidden monster there! if you are blind or the monster is a sea creature hiding in water.
 * Wait! There's something there you can't see! - for invisible monsters, especially when blind.

These messages also humorously appear when you are polymorphed into a monster capable of one of the first two forms of hiding (or after eating a mimic corpse); in this case, it will address the monster attempting to walk where you are hiding (Wait, foo! That gold is really a small mimic named !).