(Noun) A person, usually a male, who aggressively pursues anal sex, and other forms of anal sodomy with foreign objects. The butt killer does not discriminate on the basis of gender; he goes both ways. While not always engaging in rape, a butt killer will nonetheless resort to rape in the absence of a willing partner. Consent is immaterial to the butt killer. The butt killer is generally very rough and enjoys demeaning his partners/victims.
"Stay away from that guy. He's a true butt killer!"