By means of this spell, the caster is able to change a specially prepared staff into a treantlike creature of the largest size, about 24 feet tall. When the priest plants the end of the staff in the ground and speaks a special command and invocation, the staff turns into a treantlike creature with 12 Hit Dice, 40 hit points, and Armor Class 0. It attacks twice per round, inflicting 4d6 points of damage with every successful attack. The staff-treant defends the caster and obeys any spoken commands. However, it is by no means a true treant; it cannot converse with actual treants or control trees. The transformation lasts either for as many turns as the caster has experience levels, until the caster commands the staff to return to its true form, or until the staff is destroyed, whichever occurs first. If the staff-treant is reduced to 0 hit points or less, it crumbles to a sawdustlike powder and the staff is destroyed. Otherwise, the staff can be used again after 24 hours and the staff-treant is at full strength.
To cast a changestaff spell, the caster must have either his holy symbol or leaves (ash, oak, or yew) of the same sort as the staff.
The staff for the changestaff spell must be specially prepared. The staff must be a sound limb cut from an ash, oak, or yew tree struck by lightning no more than 24 hours before the limb is cut. The limb must then be cured by sun drying and special smoke for 28 days. Then it must be shaped, carved, and polished for another 28 days. The caster cannot adventure or engage in other strenuous activity during either of these periods. The finished staff, engraved with woodland scenes, is then rubbed with the juice of holly berries, and the end of it is thrust into the earth of the caster's grove while he casts a speak with plant spell, calling upon the staff to assist in time of need. The item is then charged with a magic that will last for many changes from staff to treant and back again.
Notes: Common for druids (PHB).