Undeniably one of the sneakiest and scariest ASSassins of the world. Known for being able to PENETRATE the most secure facilities in the world with incredible ease with the sole intention of raping man ass. Butt ninjas have super human abilities allowing them to walk through walls, turn invisible, cling to ceilings, and run faster than light... translation: they will have sex with your butt no matter what.
Bro-1: "I was too afraid to shower at the empty gym last night. I kept thinking I saw a butt ninja out of the corner of my eye."
Bro-2: "That's a lie, a butt ninja would've never gotten spotted by a douche like you. Probably just a normal rapist."
Bro-2: "That's a lie, a butt ninja would've never gotten spotted by a douche like you. Probably just a normal rapist."
by pokstad January 26, 2008
by poopOnsatan April 26, 2003
by theylimek May 11, 2010
I was in the middle kissing her when this BUTT NINJA comes out of nowhere and kills the mood! I was so embarrassed.
by MR.ZERO July 24, 2011
dude your mom is a butt face ninja monkey
by cris rock September 23, 2010
An unexpected, very rapid punch to the buttocks - typically for retribution - most often achieved while walking up a staircase. "Ninja butt-punch" is quickly, quietly spoken by the attacker as he makes his move, with "BUTT" heavily accented as the fist makes contact.
by alftoid January 5, 2010