Polymorph

Polymorphing transforms items or characters into different types. For example, a rock can be polymorphed into a scroll, and a human can be polymorphed into a buffalo. There are various methods of polymorphing and of controlling polymorph.

Drinking from fountains or stepping through magic gas (from a magical mushroom, staff of wonderous smells, etc.) could possibly give the character Polymorphing, PolyControl, or both.

Items

Wand of Polymorph

You can polymorph characters (including yourself) and items with a wand of polymorph.

Zapping a wand of polymorph will polymorph any objects or creatures within a 5 block range. Up to five items on each block (the five closest to the ground) will be polymorphed. Some items can not be created in this method, such as scrolls of charging. Some creatures, mainly the named creatures, cannot be polymorphed.

Applying or otherwise destroying a wand of polymorph will polymorph any objects or creatures in a 3x3 grid centered on the wand.

Ring of Polymorph

Wearing a ring of polymorph will cause the character to polymorph randomly. However, it does not give the character PolyControl, so it is risky.

Chameleon Whip

A chameleon whip will sometimes have the effect of polymorphing the creature which is hit by the whip.

Monsters

The only creature that polymorphs on its own is the chameleon. Chameleons will polymorph when they feel threatened, and can polymorph into any non-named monster.

However, eating the corpses of mutant bunnies, mutant asses, and chameleons will bestow the Polymorphing state upon the player. Eating giant mushrooms will also sometimes have this effect.

PolyControl

PolyControl is a state which allows the character to choose which creature they polymorph into. The easiest way to be permanently in this state is to wear a Ring of PolyControl. You can also temporarily have PolyControl by eating a magical mushroom or drinking from a Fountain. You may not polymorph into named characters.

Wielding Valpurus's Justifier will also bestow PolyControl on the character.

It is not possible to control polymorphing of items.