Antichickenator

Antichickenator is a unique spell that appears in the original Baldur's Gate and its enhanced edition. The spell is known only by Thalantyr the Conjurer, who will only cast it as part of a quest involving his one-time apprentice, Melicamp.

The spell was created to try and break the curse attached to an ancient set of gauntlets, presumably of Netherese origin, that Thalantyr had uncovered during his adventuring days, which would irrevocably transform anyone foolish enough to wear them into a chicken. Its precise components are unknown, but Thalantyr admits that it was at least partially based on the spell Reincarnation, and as such requires a skull taken from an undead skeleton as a material component; this serves as the "dead" element that fuels the spell's efforts to alter the form of the target back into their human shape.

Despite Thalantyr's best efforts, the spell was notably unstable, being as likely to messily kill the target as to successfully restore them to humanity.