Who is Haymitch in 'The Hunger Games'?

Haymitch Abernathy is Katniss and Peeta's mentor in The Hunger Games. His job is to manage their sponsor gifts and work out their strategies in the arena. He is described as a "paunchy, middle aged man" and was the victor of the 50th Hunger Games. At first Katniss dislikes him because of his constant drunkenness and unwillingness to help the tributes, but eventually she begins to sympathize with him, especially as she realizes the consequences victors endure for their actions.
Haymitch was Peeta and Katniss's adviser and trainer in a way. He is also the last person from district 12 to win the hunger games. He is also an alcoholic in the book.