A person's temper is literally set off by a hair trigger on his body.
However, his temper gets on the villain's nerves so hard that he's let go.
After overreacting too many times, Bob takes anger management classes to help him become a calmer person. This works for awhile, but something triggers his rage again and he relapses into his old ways, only to retake his anger management classes. Repeat as many times as you like.
Charlies attacker turns out to not be Bob, it is someone trying to frame Bob.
Averted: Alice slights Bob. Bob calmly shrugs it off.
Enforced: Bob needs to be humorously over-the-top so that when Dave has road rage later in the series and needs Anger Management classes, people will take it seriously.
Lampshaded: "Are you seriously trying to stiff me on this (Bleep Censor) payment? You've known me for ten (Bleep Censor) years and you think I'm gonna take that (Bleep Censor) quietly?"
Invoked: Bob is in a show-within-the-show where he plays the Hair-Trigger Temper and does the routine so he can stay in character.
Defied: Bob takes Anger Management classes and resolutely tries to control his temper.
Discussed: "Watch what you say to Bob. He's got a short fuse."
Conversed: "Ever notice how some people seem to blow up at the smallest thing?"
Bob's violent demeanor means no one misses him when he gets captured by the Big Bad after finding out their latest nefarious plan.
Reconstructed: Bob, after recovering from his ordeal, decides to undergo Training from Hell or find a Bigger Stick so that no one can stop him again. Not only is he no calmer - he may in fact treat the beatdown as My Greatest Failure, but as another reason for rage instead of sorrow - but he now also has more violent power to back up his temper. Nice Job Breaking It, Hero.
Played For Laughs: Bob's reactions of anger are really funny.
Played For Drama: Bob's reactions are not funny, people get hurt or killed.
Hurry up and press the friggin' button to go back to Hair-Trigger Temper or else I'll get really angry!