The "curly-haired guy" is a nickname given to one of the passengers who sat in the Tail Section of Oceanic Flight 815. The Tail Section tore off and landed on a different side of the Island than the plane's middle section. This group of surviors, who became known as the "Tailies", were the first to be bombarded by the Others. In their first night on the island, three of the tailies were kidnapped. The "curly-haired guy" was among these three tailies, according to Nathan:
NATHAN [entering]: Look, 3 of the people are missing -- the blond guy, the curly-haired guy, and the German who was helping us with the injured.