The Carnwennan is a craftable, non-consumable Hardmode throwing weapon that can autofire. Each use throws a volley of three daggers that arc downwards after a considerable distance.
Like most non-consumable throwing weapons, using this weapon builds up an exhaustion meter that appears below the player. Not using the weapon will make the meter slowly go back down. However, if it becomes completely filled, the user will be inflicted with the Exhaustion debuff, causing all non-consumable throwing weapons to deal massively decreased damage for some time. The meter resets after the debuff ends.