A person who kills three or more people at different times with a cooling off period in between.

Some one who hates cereal

A human being, usually an adult white male in his late twenties, who has killed four or more individuals in seperate incidents with a cooling off period in between.

Serial Killers come in several types. There are Hedonistic serial killers, who enjoy causing pain and suffering.

Visionary killers are often psychotic, and beleive they are acting on orders from a higher entity.

If left unchecked, a serial killer may degenerate into a spree killer or mass-murderer, which are entierly different things.

having the inability to run after people you wish to kill

1. Noun version of the perpetual 'be killing'
2. Someone who continuously 'kills' (does beyond well) in their respective field
3. The highest level of perpetual, premeditated awesomeness.

Any guy who is ugly

A person who commits a series of murders to a number of people. Many of them are very bright and intelligent. Usually, it is poor upbringing and confusion; that leads them to do these things. (note: I am not dignifying or condoning them.)