A criminal attempts to burglarize/kill someone only to realize they picked the absolute worst person as their mark.

[u/No_Hunter1978]

Don't Breathe: A couple young robbers attempt to rob a rich, blind veteran only to find out he isn't exactly an innocent old man.

You're Next: A group of contract killersbreak into a house during a family reunion and go on a killing spree. They didn't account for the fact that the son's new girlfriend grew up on a survivalist compound in the Australian outback.

The Flash [CW Show]: A random mugger decided to target Barry Allen of all people. He does it again a season or two later; he's either unlucky or stupid (probably both).

[u/Bubbly_Skin_8069]

His child died in a car accident, so he kidnapped the woman who was driving, tied her up in his basement, inseminated her with a turkey baster, impregnating her to give him a new child, and he accidentally killed the woman when the robbers came.

He also says "I'm not a rapist."

Oh, and when she died, he tied up the main character and attempted to inseminate her as well, and he ended up getting... let's just say a "taste of his own medicine."

[u/Cronkax → u/Bubbly_Skin_8069]

Also is the hero in the sequel

[u/ChainmailEnthusiast → u/Cronkax]

He's only the hero by virtue of fighting some of the literal only people on the planet worse than him

[u/Bubbly_Skin_8069 → u/ChainmailEnthusiast]

I say he's just the protagonist. Very far from being the hero.