Psychopaths

In addition to battling thousands of zombies, Frank West must also deal with psychopaths, humans who have either gone mad due to the zombie outbreak or are otherwise corrupt or evil, and who serve as the game's bosses. Examples include a clown who became insane after seeing his audience being eaten, a manager of a food mart obsessed with keeping it clean and free of vandalism, a deranged butcher who thinks zombies are "spoiled meat" and humans are "fresh meat", and a Vietnam War veteran stuck in a war flashback after seeing his granddaughter eaten by zombies.

While the term psychopath is used as an umbrella term for all of the game's bosses, most of these are simply immoral people. Only a few of them are actually driven mad by the outbreak (Adam, Cliff, Steven), most of them are simply corrupt people taking advantage of the situation (Jo Slade, The Convicts), Others are simply overcautious (The Hall Family). Brock Mason, in particular, is not mad nor immoral, but simply a soldier carrying out his orders. Likewise, Cletus Samson was not driven mad by the outbreak, but simply has trust issues with humans and may also be unable to distinguish a zombie from a human. This is further supported by the fact that, in the Wii edition, Cletus can be saved.

Avoidable Psychopaths
In addition, there are a few more psychopaths Frank can fight to gain additional bonuses, such as PP points, special weapons, and other achievements.

Unavoidable Psychopaths
Aside from these, here are also only three that Frank actually has to fight and he cannot avoid them no matter what. :