Why is Cato from Hunger Games a villain?

Cato is not a villain in The Hunger Games. He is a tribute from District 2, and like Katniss Everdeen, he is fighting for his life in the Hunger Games. While Cato does kill other tributes, he does so in order to survive. He is not a villain in the traditional sense, but rather a product of the harsh and violent world of Panem.