The infernal harpoon is an improved version of Dragon harpoon. It is made by using a Smouldering stone on a Dragon harpoon, which requires level 85 Cooking and 75 fishing, giving the harpoon 5,000 charges. Doing so grants 350 Cooking xp and 200 Fishing xp. Making the Infernal harpoon is irreversible.
The Infernal harpoon can be used as a weapon or to catch fish. Fishing with it gives a 1/3 chance for the fish to be cooked as it is fished. This will consume the fish and will grant half of the Cooking experience that would normally be granted when cooking the fish. If all 5,000 charges are used on raw sharks, 525,000 Cooking xp will be gained.
The Infernal harpoon possesses the same special attack as the Dragon harpoon, which requires 100% special attack energy and boosts the player’s Fishing level by 3.