Kate: What are you trying to say? That all Monsters look the same to you?! Huh? HUH? HUH?!
Seems to be a sore spot for Gary Coleman too, although he gets even angrier if reminded of what his parents did to him.
Cyrano's nose in Cyrano de Bergerac: In Act II, his fellow cadets claim that even using the word "nose" is sufficient to send him into a murderous rage. The worst it does onstage, however, is trigger a stream of Unstoppable Scathing Sarcasm where he comes up with an impromptu list of 20 better jokes than "Big Nose." Cyrano was also about to throttle Christian for testing just how far he could push him with a hurricane of nose puns and only stopped when he realized who he was. It's present in the remake movie Roxanne, as well.
In The Effect of Gamma Rays on Man-in-the-Moon Marigolds (now that's a Long Title), Ruth mentions her mother's high-school nickname, Betty the Loon. It doesn't end well forRuth or for her pet rabbit.
In Hamlet, the usually meek and passive Gertrude will explode if her husband Claudius is ever insulted ("You have your father much offended") or threatened ("Oh this is counter you false Danish dogs.") She's still fairly ineffectual though.
Nathan in Sweet Gay Baby Jesus seems much more calm and level-headed than his boyfriend, Jed- until said boyfriend's actually threatened, and then he mashes thing up with a golf club.
In Twelfth Night, Orsino very nearly loses it when he hears that his lady-love Olivia has married his page, Cesario. However, careful listening to his monologue reveals that what he's really mad about is losing his page.
Wicked: Galinda is terrified and upset when she doesn't get her way.
Despite the fact that his Character Song flat-out states that he's stupid, Fiyero becomes furious with Elphaba when she treats him like he is after they rescue the lion cub:
Fiyero: Boy, you think I'm really stupid, don't you?!
Elphaba:[surprised] Well, not really.
Into the second act, Elphaba becomes his Berserk Button, even lashing out at Galinda for appearing so unconcerned about her best friend's disappearance, status as enemy of the state, and the vast amount of rumours about her - like the one where pure water will melt her...
Mistreatment of people and Animals also sets her off, which is what causes - well, at least half of the problems in the play. She even starts a fight with Glinda for talking about Fiyero as if he were her property.