Gaston is not only the antagonist of Beauty and the Beast, but also a villain.
He spends the entire musical trying to find ways to marry Belle. He just wants to marry Belle because she is the prettiest girl in town. He can be quite funny at times. When Belle proves that the Beast is real, Gaston wants to kill the Beast and makes the citizens believe that the Beast is real and he only does that because he can tell that Belle loves the Beast and that is one of his ways to get Belle to marry him. He nearly almost killed Beast in the end, but Gaston in the end does die by falling off the castle. So the musical if you think about it, it is a love triangle between Belle, Beast, and Gaston: it can be hard to pick up a lot of the time. Gaston is a funny villain. Gaston is the real beast in Beauty and the Beast.