(Noun) people, typically a male, just who aggressively pursues anal sex, also forms of rectal sodomy with foreign things. The butt killer doesn't discriminate on the basis of gender; he goes both techniques. While not constantly participating in rape, a butt killer will none the less resort to rape in absence of a willing partner. Consent is immaterial towards butt killer. The butt killer is generally very rough and enjoys demeaning their partners/victims.