Villains who are willing to commit murder and/or have done so at least once, or attempted to do so; the act must be deliberate and not in self-defense or during war-time situations. Not all murderers fall under this category if the "murder" was unintentional (e.g Manslaughter or Inderect Murder) and they show no desire to kill otherwise.

Be they hitmen or thrill-killers, these characters all share one common trait: the willingness to kill in cold blood, making them very dangerous and cruel, even in a realm of criminals and wrong-doers.

This category also applies to villains who merely threaten to kill someone if that person does not carry out the wishes, but don't once that person complies.

By default, the following villains go into this category:

• Murderers: villains who have killed one or two individual(s). Example: Alec Trevelyan.
• Serial Killers: the step above Murderers; is for villains who have killed 3 or more people with "cooling off" periods between each murder. An example: Hannibal Lecter.
• Terrorists: villains who have usually committed mass murders, killing 3 people or more at the same time. An example: Joker.
• Genocidal: the step above Serial Killers; is for villains who seek to exterminate (or have successfully exterminate) a whole race or community. An example: Azog.
• Cataclysm: the step above Genocidal; is for villains who wish to end their planet(s) or universe(s), and in consequence ending all life. This type of villain is one of the extreme (and obviously worst) variants of Homicidal. An example is Abyss Trinity who wishes to destroy his own world.

Notables variations:

• Attempted Murderers: Villains who have admitted to, or been charged with, the crime of attempted murder, but have never actually succeeded. They may plan to kill someone and be thwarted, or go on homicidal rampages, but miserably fail and only injure people. Usually, those kind of villains are used for comic purposes. However, they can be just as dangerous as regular murderers, but simply incompetent. Many cartoon villains fall under this category.
• God Killers: villains who have literally committed "deicide"; that is to say, in some capacity, they have killed some form of deity (god) for a anarchist goal or to usurp his position. Usually, only deities, cosmic entities or supreme gods can defeat beings of similar strength. An example: Kratos.
• Child Murderer: villains who have murdered prepubescent people (who are 12 years old or younger; including infanticide, which is the murder of babies). It is one of the worst possible things one can do (even if the child was a villain too, because it is much easier to rehabilate children, with some exceptions). Killing children is usually an instant Moral Event Horizon crossing, which means that villains who commit this on a regular basis are almost always Pure Evil. An example of this type of villain is William Afton aka the Purple Guy of Five Nights at Freddy's, or the Staff Leader. 
• Animal Killers: villains who have killed animals. This is usually considered a highly unpleasant and vile act of evil, as most animals have less chance of defending themselves against danger. Due to many cultures using animals as livestock obviously the act of "animal murder" is restricted to when someone kills a pet or wild animal not used for food or other produce (for example a poacher killing an elephant for ivory is not an animal killer as they do it for monetary gain rather than senseless cruelty).