Polymorph

Version 0.13: This article may not be up to date for the latest stable release of Crawl.

Polymorph
Level	4
School1	Transmutation
School2	Hexes
Source(s)	Book of Transfigurations
Casting noise	3
Spell noise	0

This spell randomly alters the form of another creature.

Polymorph is a Transmutations spell which, if used on a natural, holy, demonic, or plant monster, will transmute it into another monster of the same category, usually with the same or slightly higher HD. Some chaotic creatures are special cases: ugly things simply change their color, while shapeshifters and glowing shapeshifters will heal some HP and change form. The resulting monster can't be a unique, undead, pandemonium lord, statue, derived monster (those with different values for their monster type and species fields: non-base orcs, non-base draconians, etc), a monster that doesn't provide any experience, or a monster that belongs to the no poly category.

If Polymorph is used by an enemy on a player who fails to resist, the player will suffer a temporary bad form transformation. Mutation resistance is useless against this, but magic resistance and worshiping Zin may protect you.

Followers of Zin incur a piety loss and a penance if they cast this spell.

Similar effects can be achieved with a wand of polymorph, the attack of a chaos weapon, the Plutonium Sword, and some Transmutations miscast effects.

Strategy

Good Targets

This is a partial list of good targets for spells, wands or clouds of polymorph other - that is, monsters which are unlikely to become more powerful when polymorphed, i.e. monsters which are low-HD, high-threat.

• Electric eel - They'll turn into a less dangerous flying or water-capable creature.
• Red wasps and yellow wasps - If you lack poison resistance these can be very nasty.
• Moth of Wrath - They can turn a crowd of weaklings into a berserk mob.
• Boggarts (and other low-HD summoners) - Although fragile, summoners can bring lethal reinforcements into play. Fortunately they have low enough HD that the polymorph results are usually pretty pathetic.
• Jelly - Polymorphing is an effective means of avoiding their corrosive attacks.
• Harpy - An option if you have issues dealing with very fast monsters.
• Oklob plant - Usually turns into a wandering mushroom.
• Sigmund (and other well-armed uniques) - If he turns into anything but a humanoid, his branded scythe, spells, and wands will be useless.

Bad Targets

These are monsters that are actually considerably less threatening than monsters of similar or slightly higher HD.

• Hydra - These often become storm dragons or guardian serpents. Even if you have problems with hydras, these alternatives are worse.
• Slugs - They have very high HD. An elephant slug has the same HD as a titan. The results will not be pretty.
• Adders or other inoffensive creatures - you'd really rather have a boggart?
• Worms - They may hit hard early on, but they're slow and you'll soon outgrow them. But they do have fairly high HD, and a human hits harder and is much faster.
• Slime creatures - A single one can turn into a giant orange brain or a storm dragon. Larger versions can turn into multiple such creatures.
• Grinder - He has unusually high HD for such an early unique, and many of potential polymorph forms are quite dangerous, up to some tier-2 demons. Grinder the hellion or Grinder the tormenter is much worse than Grinder.
• Mennas - High HD and being holy give him a near guaranteed chance of turning into an extra deadly Pearl Dragon. Roasting you on holy flames will offset the loss of his equipment.

History

In 0.14 it will become a monster-only spell.

Prior to 0.12, this spell was called Polymorph Other. When used on the player by a monster, it had the same effects as Malmutate.