A Chilfos is an icy, humanoid enemy found exclusively in Twilight Princess. From medium to long range it will throw its spear at Link, regenerating one every four or five seconds. In close combat it will just use its spear as a sword. It defends and attacks with its lone weapon. When its spear breaks, a new one is automatically regenerated. The Chilfos will be at full health again when a spear is regenerated.
Especially in groups, they are troublesome to defeat. The best approach is to take them on one at a time. Link can easily dispatch a Chilfos by targeting it, and performing the Helm Splitter technique. From long range, he may also shoot it twice with Bomb Arrows, one to break its spear, and another to finish it off. The spear will regenerate after being broken, so he must be wary.
When he is trying to shoot this enemy from a medium distance with a Bomb Arrow, there is one cool little trick to just use one Bomb Arrow. Link must stand close enough to it that it will throw his spear at him. He needs to wait until it throws its spear and then quickly counterattack with a Bomb Arrow. He can avoid the thrown spear by using Z-targeting. When he hits the Chilfos before it can regenerate its spear, it will die instantly.