To clarify, there is a teenage mutant ninja turtle - a children's cartoon, and then there's "the ninja turtle". The ninja turtle is the act of taking your ballsack testicles included and flipping it around so that it sits on top of your johnson. It's best achieved on a warm day when things are hanging lose. The term originated at the University of MD fraternity scene. The ballsack resembles a turtle shell and the johnson is the turtle's head peeking out.
Jim was so drunk that he pulled down his pants and demonstrated the ninja turtle in an attempt to get Cindy's attention. But he failed miserably and went home and pulled his pud instead.
A large slice of pizza similar to that seen in the opening scene of Ninja Turtles II: Secret of the Ooze at Ray's Pizza. Typically a Ninja Turtle slice would be at least 1/5 or 1/4 of the entire pizza.
Dude, I just tried a new pizza place and they had ninja turtle slices.
Having sex while wearing your partner like a backpack, thereby resembling the shell of a turtle. Often performed with people who have ninja turtle names, and are little bitches who can be carried around like a baby.
Raph got so NinjaTurtled last night when I used a strap on to fuck him in the ass while he wore me like a back pack.