Elizabeth Halsey (Diaz), a bitchy stoner and supposed educator, shouldn't sell herself short: "Bad teacher" barely scratches the surface of her accomplishments. She's a bad fiancée, rightly dumped in the film's opening minutes for being a gold digger. She's a bad feminist; post-breakup, her plan B is to raise enough cash to buy bigger tits – the better to snare "a man who will take care of me," she figures. Broadly speaking, she's just a bad person – a liar, an embezzler, a master manipulator. Fun stuff, I tell ya. Diaz wisely sidesteps her good-times-gal public persona to kickily embody a human-sized callus that’s impervious to emotion, a cancer who lays waste to everything that gets in her way. When a colleague who’s been ignored previously by Halsey cracks a spiteful joke, Diaz's eyes spark – it's as if cruelty is Halsey's aphrodisiac – and the moment is at once chilling and thrilling. The bulk of Bad Teacher isn't so subversive – Gene Stupnitsky and Lee Eisenberg's script is basically Bad Santa's public-school analog – but it is consistently funny. Its trash-can humor is tasteless, no doubt, but hey, that doesn't make it unpalatable.