Conal Cochran

Conal Cochran is a fictional warlock and a one-time antagonist featured in the Halloween film series. Played by actor Dan O'Herlihy, he appeared in the 1982 feature film Halloween III: Season of the Witch.

Overview
Conal Cochran was a warlock and cult leader, as well as the CEO of the Silver Shamrock Company. Using trace minerals taken from the slabs at Stonehenge, he mass-produced a supply of Halloween masks that, when prompted at a specific time on Halloween night, would transform all children who are wearing them into sacrifices to the Celtic god Samhain.