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 survivors, 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 by the Others. The "curly-haired guy" was among these three tailies. Although he was not specifically identified in any scene, he was later mentioned by Nathan: