Disguise undead

Disguise undead was an arcane spell that crossed multiple schools of magic including alteration, illusion, and necromancy. It altered the appearance of one or more undead creatures so they could pass for live, healthy creatures.

Effects
The number of undead creatures that could be affected by this spell was equal to the level of the spellcaster. Each target grew flesh, organs, hair, and skin to resemble what they looked like when alive and healthy, although if deformed in life then the disguise included those deformities. The flesh looked and felt as expected for the type of creature, although it did not bleed, sweat, or smell. No abilities were granted to a target. If it could not speak while undead, then this spell did not grant the ability of speech, etc. Abilities that relied on smell or appearance, such as the nausea-inducing odor of a ghast or a fear-inducing visage, were negated by this spell. The spell took a full ten minutes to cast and lasted ten minutes per level of the caster. Also, all targets had to be within 10 yd (9.1 m) per level of the caster.

The oldest version of disguise undead was very powerful, combining alteration, illusion, and necromancy in a way that prevented detect undead (but also attempts to detect life) and turning for the duration of the spell. Even trying to divine the alignment of a disguised undead returned nothing or complete neutrality. The only drawback was many additional material components.

When wizards began to specialize in one particular school of magic, this spell ironically became difficult to impossible for necromancers and illusionists to learn because they were in a school diametrically opposed to the other specialty required to cast this spell. The result was that the later version of disguise undead did not prevent detect undead or alignment detection, and clerics and paladins could attempt to turn disguised undead once they realized the nature of what they were facing.

Components
Both versions of this spell required verbal and somatic components. Material components for the earliest version were a drop of the caster's blood, a pinch of dust, a smudge of ashes, a bit of flesh, a sliver of bone, a human hair, and the cocoon of an insect. The newer, weaker version required only the insect cocoon.

History
This spell was published in "Volo's Guide to All Things Magical" and became generally known to the magical community.