Underestimating Badassery

We, the audience, know just how awesome the badass is, whether they look the part or not. Unfortunately, not everyone else in the story does, even when the former is the case. So maybe our hero walks into a bar, where some of the regulars don't take too kindly to him. Or maybe a couple of thugs accost him on the street. Sure, he might look dangerous, but he's outnumbered and outgunned, so he shouldn't be a problem, right? The viewers watch with bated breath for the moment that these guys find out that they've woefully underestimated the level of badassery involved. Let the curb stomping begin. Compare Beware the Nice Ones; Good Is Not Soft; The So-Called Coward; Mugging the Monster; You Wouldn't Shoot Me; Dude, Where's My Respect? and Crouching Moron, Hidden Badass. For the villainous example, see Not-So-Harmless Villain and Do Not Taunt Cthulhu. For the video game version see Suicidal Overconfidence. Contrast with Bullying a Dragon, where the perpetrator antagonizes someone despite knowing full and well how Badass they are and without any perceived advantage, and Badass on Paper and Mistaken for Badass, cases of Overestimating Badassery. No Real Life Examples, Please!