Changestaff

You focus natural energy and change a specially prepared quarterstaff into a Treant. When you plant the end of the staff in the ground and speak a special command, your staff turns into a Treant. The Treant is friendly to you and your companions. Roll initiative for the Treant, which gets its own turn. It obeys any verbal commands that you issue it (no action required by you). If you don't issue any commands to it, they defend themselves from hostile creatures, but otherwise take no Actions. The DM has the creatures' Statistics. 

The Treant does not have access to it's Animate Trees feature.

 If the Treant is reduced to 0 HP before the end of the spell, it crumbles to powder and the staff is destroyed.