Antagonist
Character Role Analysis
Creon
If Antigone is the protagonist that means Creon has got to be the antagonist. And he's a real jerk. He's the force that Antigone goes up against.
Although, that being said, there are some that see him as a possible protagonist (check out the Character Role of Protagonist for more deets). We'd just like to point out, however, that it is Antigone—not Creon—who disturbs the world by breaking her uncle's law. Antigone drives the action, while Creon only reacts. He is constantly trying to rebuff Antigone's forward motion, rather than creating any of his own. This in our mind makes him seem like the most likely antagonist. Once again, there's room for debate. Antigone just doesn't fit snugly into all of Aristotle's ideas.