Killers

killer - someone who causes the death of a person or animalkiller - someone who causes the death of a person or animal
slayer
individual, mortal, person, somebody, someone, soul - a human being; "there was too much for one person to do"
executioner, public executioner - an official who inflicts capital punishment in pursuit of a warrant
eradicator, exterminator, terminator - someone who exterminates (especially someone whose occupation is the extermination of troublesome rodents and insects)
choker, garroter, garrotter, throttler, strangler - someone who kills by strangling
liquidator, manslayer, murderer - a criminal who commits homicide (who performs the unlawful premeditated killing of another human being)
poisoner - someone who kills with poison
regicide - someone who commits regicide; the killer of a king
felo-de-se - a person who kills himself intentionally