The caster spits, and whatever is struck grows a magical mouth. Unwilling targets can attempt a physical save, and an attack roll may be required against canny opponents lest you grant a mouth to their breastplate.
This mouth allows the target to speak, imbibe potions, and do whatever it is a mouth could. Most objects have very little to say, although when working the spell the caster can imbue a short message to be spoken by the mouth. Sabtah used this spell to repair damaged equipment by feeding healing potions to delicate alembic.