Cow ninja 

A cow who is a ninja and stands on motherfuckers who try to mess with him. A cow ninja is also a fast cow who knows how to handle his weapons and use his speed to propell him/herself onto walls, basically running on walls.

"Omg look a cow ninja!" says the kid
"moo" shink!!
the cow says "another head gone, moo"

Cow ninja by Yoer November 14, 2007

Ninja Cow 

An asshole and bastard. Many have tried to combine the two and create the "Basshole", but that is simply silly.

You are such a Ninja Cow, Nova!

Ninja Cow by Ninja Cow June 20, 2004