The following are heroes that, while still generally fighting on the good side, are more than willing to kill another being. In order for this to be considered different from cold-blooded murder, the individual said hero kills is almost always corrupt or criminal in some fashion or they kill in self-defense.

These heroes are usually very strict in terms of not killing innocent people and can be considered in some ways like soldiers or Evil exterminators. They will not hesitate to end the life of a wicked or crazed opponent if they feel it will save the lives of themselves or innocent people.

They're the opposite of Merciful and Pacifists, and also the good counterpart of Homicidal villains.

Reasons of a character of being a lethal hero:

• The hero eventually killed the villain who they originally decided to spare after a fight, only for the villain attempted to backstabbed the hero as they turned their back on the villain that prompt the hero to do so. The way the hero killed the villain may be done out of reluctance.
• The hero reluctantly killed the villain due to non-lethal solutions had been exhausted and that the villain in question proved to be a Pure Evil person that must be destroyed with one way or another.

NOTE: Characters that kill in cold-blood, with no concern about "innocence" are murderers and serial killers, even if misguided. Lethal Heroes always have strict codes concerning who/why they kill and VERY few Lethal Heroes enjoy killing (e.g. Venom), indeed they often hate the act but do so out of duty or survival. However, Pure Good heroes are never lethal, no matter how heinous the villain is. Even if they take at least one life, then that "murder" is either out of self-defense, in equitable fight, as a last resort and/or in wartime situations with regret and remorse, and/or protecting someone and/or even can be an accident. If those are cases they should go under Dreaded, Vengeful, Wrathful and/or Chaotic Good instead of this category. (e.g. Tommy Oliver, Geki, Mario, Kirby, Yoshi, Terry Bogard, Captain America, Black Panther, Samurai Jack, Preston Garvey, Fox McCloud, Yoda, Link, Fa Mulan, Jonathan Joestar, Captain Rex, Ronald "Red" Daniels, Qui-Gon Jinn, Aragorn, Po, Superman, and Gizmo)

• However, lethal heroes can still by sympathetic if they are harsh only towards people whom they see as enemies while usually kind and benevolent toward everyone else (e.g. Sidney Prescott, Clementine and Alan Grant).

Heroes do not necessarily have to kill someone to qualify, some of them just have the potential to do so and can be seen violently attacking someone else (e.g. Lucy Wilde, EVE (WALL-E)).