What nickname had everyone at Beecher Prep given Auggie?

Take your pick. "Rat-boy," "Freak," "Monster," "Freddy Krueger," "Gross-out," "Lizard face," and "Mutant" are just some of the cruel nicknames liberally dished out to Auggie by the other kids. He's heard them all before, and many more besides. Auggie's facial disfigurement means that he's always been the butt of snide remarks. On top of everything, Auggie's given the hurtful sobriquet Darth Sidious by the loathsome Julian. Auggie's antagonist knows that he's a big Star Wars fan, and so he also knows that this particularly unpleasant nickname will really hurt. If you've ever seen Darth Sidious you'll know he's not exactly drop dead gorgeous. If you haven't, then think of a word that rhymes with "Sidious" and you'll soon get the idea.
In one particularly upsetting episode, Auggie overhears Julian and some other boys talking about him, saying how ugly he is and how they'd really hate to look like him. It's Halloween, and one of the boys is wearing a Darth Sidious mask. Another one is wearing a mummy costume; he complains about Auggie following him around all the time. Auggie is devastated; he now knows that underneath that costume is Jack, someone he thought was his friend, someone he could trust. But it seems he's just like all the others.