It's yet another year at Hogwarts with Harry's arch-nemesis Draco Malfoy. In addition to being his spoiled, bratty self, Draco shows off a bunch of his other negative personality traits this year.
For the first time, we get to see that Draco is really prejudiced. Sure, he never liked Harry, Ron, and Hermione, but this year he actually starts tossing out nasty slurs:
HERMIONE GRANGER: At least no one on the Gryffindor team had to buy their way in. They got in on pure talent.
DRACO MALFOY: No one asked your opinion, you filthy little Mudblood.
He doubles down on this when he sees that Mrs. Norris has been petrified and he says, "You'll be next, Mudbloods." Yikes. Why do we get the feeling he's about to light up a torch and start marching and chanting in a wizard supremacist rally or something?
Because of Draco's pure-blood pride, Harry, Ron, and Hermione think he might be the heir of Slytherin and so they brew up a Polyjuice Potion to find out. As Crabbe and Goyle, they're able to see how Draco acts with his actual friends in unguarded moments and it… actually isn't that different.
Even to his two friends, Draco is still bitter and bossy and a bit of a jerk. He steals a present that someone left in the Slytherin common room and snaps at his pals if they dare disagree with him. It's weird but we actually sort feel sorry for Crabbe and Goyle. Being friends with Malfoy just seems exhausting.
But you might feel a little bad for Draco, too. After we meet his father, we understand the kind of family Draco grew up in. If you had a dad who constantly told you that Muggle-borns were scum and you were awesome because you were rich and pure-blood and your last name was Malfoy, you might start to believe those things, too.
So, maybe Draco doesn't want to be a jerk, but he's been raised to be one his whole life. Dumbledore says our choices are most important—what will Draco choose to be in future movies?