How do I get the Harpoon in Shadow of the Colossus? Shadow of the Colossus Guide, walkthrough

Harpoon of Thunder can only be used after beginning a New Game+ on Hard difficulty level. Moreover, you need to defeat two colossi in Time Attack mode. Unfortunately, you cannot use it during other Time Attacks.

The Harpoon is a powerful ranged weapon

To use your harpoon, equip your bow (left directional button) and press the button again. The harpoon is similar to the bow, but deals much more damage, especially when you aim at vital points. You can use the harpoon to deal up to 80% of the damage, but each vital point requires a finishing blow dealt with a sword. More info on items can be found in the "Time Attack rewards" chapter.