As the name suggests, it is a classic black pirate hat, with a Jolly Roger symbol on one side and two small white feathers in the back - ironically resembling the design of the Captain's Hat in Epic Battle Fantasy 3.
Like the Captain's Hat, the Pirate Hat provides a moderate bonus in defenses and also Water and Bomb resistances. The Pirate Hat however has slightly inferior stat boosts, and does not strengthen the power of thrown items.
Epic Battle Fantasy 4
Found in a chest in the Lankyroot Jungle.