Baku is a boss in Final Fantasy IX. After Princess Garnet is kidnapped by the Prison Cage in the Evil Forest, Zidane decides to take Vivi and Steiner to look for her. Zidane has to fight Baku alone to be allowed to leave Tantalus.
Zidane should defeat Baku with physical attacks and use Potions should his HP become low.
Steiner's Iron Sword can be stolen from him, making the boss battle with Plant Brain much easier.