Changestaff

Changestaff is a transmutation spell that makes a staff become a treant on command.

Effect
When cast, changestaff prepares a specially-prepared quarterstaff into a huge treant-like creature, about 24 feet tall. When the caster plants the end of the staff in the ground and speaks a special command to conclude the casting of the spell, the staff turns into a creature who looks and fights just like a treant. 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. If the staff-treant is killed or rendered unconscious, it crumbles to powder and the staff is destroyed. Otherwise, the staff can be used as the focus for another casting of the spell. The staff-treant is always at full strength when created, despite any wounds it may have suffered the last time it appeared.

Focus
The staff used in the casting must be a sound limb cut from an ash, oak, or yew, then cured, shaped, carved, and polished (a process taking four weeks). The caster cannot adventure or engage in other strenuous activity during the shaping and carving of the staff.