Hydra Form

Version 0.26: This article may not be up to date for the latest stable release of Crawl.

Hydra Form
Level	6
School1	Transmutation
Source(s)	Book of Transfigurations Fen Folio
Casting noise	6
Spell noise	0

Transforms the caster into an amphibious, many-headed hydra for a brief duration. Its multiple heads strike in all directions. Foes slain by the gnashing teeth are instantly devoured, reinvigorating the caster in their reptilian rampage. The caster gains innate armour and increased health, and becomes resistant to poison. While transformed, any equipped weapons and armour are melded. The form's number of heads is fixed upon casting the spell, and increases with power.

Hydra Form is a level 6 Transmutations spell which turns the caster into a rampaging hydra, gaining the following:

Pros

• +30% HP
• Poison resistance
• Gain multiple heads, granting you cleaving and increased Unarmed Combat base damage (2 + (3 per head up to 10 heads) + (1.5 for each head after the tenth). The number of heads is spell power / 10, up to 20 heads
• Gain innate AC based on spell power: 6 + 5 * spell power / 100
• Ability to heal by devouring any edible monster upon kill (amount healed based on monster HD). Any monster with a corpse considered edible, including undead (ghouls, death scarabs, etc.).
• Fast swimming speed

Cons

• All equipment slots except for rings and amulets meld into the new form
• Big size penalizes evasion

Strategy

Hydra Form provides the caster with some rather extreme strengths and weaknesses for its duration. This form drastically reduces the caster's defensive stats: no armour or defensive mutations means that the caster's AC will drop dramatically, and the increase in size will make all but the most nimble and well-trained dodgers into sitting ducks for its duration.

To make up for this, the caster is given a significant boost to HP, a massive increase in damage output (assuming many heads), and a significant amount of healing each time you defeat a monster which leaves an edible corpse. At its best, this amounts to an extraordinarily powerful vampiric-branded Unarmed Combat attack that specializes in taking out large groups of enemies. Also, the cleaving effect is superior to that provided by axes (secondary opponents do not take reduced damage), and unlike with natural hydras, you only make a single attack against your target, allowing Hydra Form to devastate even high-AC opponents. Unfortunately, these factors only come together in niche circumstances.

Getting enough heads for Hydra Form to become truly devastating is difficult. Your headcount is based on your spell power and there are very few spell enhancers for the Transmutations school of magic. You cannot gain heads by having them chopped off by enemy bladed weapons, either.

The pseudo-vampiric cleaving effect is very impressive under the right circumstances (Vaults:5 is very delicious, for example), but bear in mind that areas without edible corpses suddenly render the powerful healing effect completely useless. On top of that, the healing effect only kicks in once you've killed an opponent; until that point, it does nothing. A string of unlucky misses or an encounter with a powerful, durable unique may get you killed, no matter how delicious your opponent may be.

Finally, bear in mind that the significant damage output of Hydra Form is nearly matched (at least against a single opponent) by the level 5 spell Blade Hands, particularly for characters with high strength. This alternative leaves your defenses largely untouched and is much easier to get up and running in almost all circumstances. Unlike Hydra Form, Blade Hands does have the downside of reducing your spell success rate, but this won't be an issue if you only planned on punching your opponents for the next dozen turns anyway.

As with its bigger brother Dragon Form, Hydra Form benefits greatly from support magic such as Ozocubu's Armour.

History

• Hydra form will be removed in 0.27.
• Prior to 0.26, hydra form had a very short duration. Also, this form could devour only monsters with edible corpses.
• Prior to 0.19, this form could not devour Big and Giant size monsters.
• Prior to 0.18, this form had a +8 Str bonus. Also, the number of heads wasn't fixed and the caster could grow extra heads when hit with chopping weapons. Enemies with flaming weapons could lop off the caster's heads, ending the transformation if there were no heads left.
• Hydra Form was added in 0.16.