Unicorn
A unicorn, represented by u, is a type of monster that appears in the dungeon starting at mid-game. They are very fast and tend to prance around, which often makes them difficult targets. They can also deal surprising amounts of damage.
There are three types of unicorns: white, grey, and black, which correspond to lawful, neutral, and chaotic alignments respectively. The unicorn of your alignment will be peaceful; all others will be hostile.
When killed, a unicorn leaves a unicorn horn with its corpse. Eating a unicorn corpse has a chance of giving poison resistance.
Sacrificing a unicorn at an altar is a special case and is covered in the page on altars. Basically to receive alignment and luck benefits you should sacrifice a unicorn of a different alignment than you at your own altar.
Throwing gems to a peaceful unicorn can bring luck increases as well as assist in identification. If the unicorn "graciously" accepts your gift it is worthless glass. If he "gratefully" accepts your gift it is a valuable gem.
