See that guy over there? The one that can make Your Head A-Splode with his Psychic Powers? What a weirdo. Let's throw rocks at him!
This is the fate-tempting and suicidal tendency of characters to bully, persecute or otherwise provoke people or things they really shouldn't be messing with. That weird loner who sits in a corner reading? Fine, douchebag. That "antagonist" who's really just trying to live his life and doesn't want much to do with you? Go on then, you bastard. That beautiful lady who can heal people? If you're that low, go for it (but keep in mind that you may find yourself in a position later where you need her to heal you). The blind kid that somehow knows what you're about to do and is powerless to stop you? Go for it, you donkey. Whatever floats your boat.
But the kid who can warp the fabric of reality and just wants to be left alone?
Bad idea.
Sub-Trope of Too Dumb to Live. Also a sub-trope of All of the Other Reindeer, where the character is surrounded by tormentors even though they are known to have some incredible power conducive to being a Person of Mass Destruction, and most of the time because of this. This frequently crops up in Kids Are Cruel (in which case it would be "Kids Are Cruel and Also Too Stupid to Deserve to Exist"). It's usually a way of getting us to sympathize with the main character, but, really, bullies should be smart enough not to mock the "freak" Cursed with Awesome and Super Strength. Even when logically — or at least using the basest level of human decency and the smallest inkling of self-preservation — these bullies should find a weaker target or cut the poor kid some slack. So, in a sense, Straw Bullies. Then again, Youth Is Wasted on the Dumb and the Prideful.
The Smug Snake has a tendency to do this, since their overconfidence causes them to forsake their common sense.
The Fettered especially have it bad because they choose not to fight back and often protect their tormentors from the Forces of Evil. Sometimes the bully in question knows this, and we're back to them being cowards who pick on those who can't/won't retaliate.
If the victim snaps, they will turn the tables (if not turn the table into a buzzsaw, set it spinning at hurricane-level speeds, and shove their tormentors' intestines into the spinning blades… literal tables need not be involved). Also, don't lie. It is very cathartically awesome when the bullies are finally killed off or subjected to a Fate Worse than Death as Revenge. (And, if they have not done anything remotely objectionable up to this point, this could well be taken as a case of Dark Is Not Evil.) Unfortunately, many of the times a bully attempts to go after someone of this ilk is because they are trying to elicit a response, which, in turn, would prove everyone's point about how much of a freak they truly are. Then again, in many cases, this makes them even stupider, as they don't seem to consider anything particularly awful happening to themselves as a result of their actions.
Please note: the trope need not require actual bullying (though it is a popular method). As long as the provoker or provokers intentionally and excessively antagonize someone much more powerful than they are, knowing full well beforehand just what they are screwing with, then it's Bullying a Dragon. Also, if the Dragon is a massive jerk and suffers abuse because of that, then we may be dealing with a case of Cape Busters instead. If this trope is done with the likely outcome as the goal, it's Suicide by Cop or maybe Strike Me Down with All of Your Hatred!.
Also, see Fantastic Racism. A popular Freudian Excuse and backstory for a Start of Darkness. This trope doesn't usually have anything to do with The Dragon who's the Big Bad's second-in-command (although, it might). Video Game examples where the AI keeps trying to bully you despite the power difference because it's not programmed to back down has a special trope, Suicidal Overconfidence. The Cornered Rattlesnake is weaker than a 'Dragon' and may not appear powerful or willing to fight back but can be dangerous if pushed too far.
Compare:
Did You Just Flip Off Cthulhu?: Showing defiance to something you know is about to kill you.
Do Not Taunt Cthulhu: When the entity you've been picking on retaliates by murdering you.
Mugging the Monster: If you thought you were the badass and they were an easy victim. Can evolve into Bullying a Dragon if you find out the hard way that you're outclassed but still persist in provoking further attacks. It can also exist simultaneously when the obviously intimidating and dangerous person is hiding something that makes them even more intimidating and dangerous.
Paper Tiger: An inversion in which the target looks powerful but is only putting up a façade.
Shooting Superman: Launching an attack against a target you know is tough enough to just shrug it off.
Villain Ball: Doing something stupid in the name of the Evulz.
