Originallly developed in the late '90s to replace the word "Cock". The current spelling was adapted to present a Politically Correct version, of a favored slang term. The end result is a socially acceptable version, which remains acceptable in all situations, while not sounding lame such as: Penis, Groin, Dick, or Blue-Rare-Man-Meat.
"You are a Khak-Mongrel"
"How about a nice slice of khak"