Reverse Ninja Turtle 

A sex move. To wit: You get down on your back, and you spin around. Then you take your "bow staff" and you stick it in the other guy's asshole.

And then you eat pizza.

Things were getting kind of stale between Nick and Aaron, so Aaron decided to break out the Reverse Ninja Turtle and it was like it was the first time again.

Reverse Ninja Turtle by Chip Z'hoyy April 14, 2013

one-eyed night-crawler w/ turtleneck 

Covert expression for the male (possibly uncircumcised) sexual tool.
see: one eyed trouser trout

His best catches were when he used his one-eyed night-crawler-with-a-turtleneck as bait.

one-eyed night-crawler w/ turtleneck by sonni hopkins September 7, 2005

Disco Turtle 

The act of opening a co-worker's CD drive and then flipping over their mouse, whilst calling out "Disco...turtle". This is done only for the purpose of annoying them.

The actions may be performed either by themselves or together, but if performed together, "Disco" always precedes "Turtle".

Ethan leans over Brandon's computer while he is talking to Lucas. Ethan hits the open button on Brandon's CD drive and calls out "Disco!" and then flips his mouse over, calling out "Turtle!"

Brandon says, "Dammit, I got Disco Turtled!"

Disco Turtle by King of the Water Cooler May 14, 2010

Shy Turtle 

When you let a little bit of shit come out, and then squat over someone's face, smearing your shit around a bit.

Then withdraw the poop back into your ass, like a shy turtle.

When Matt and Nick were younger, Matt used to shy turtle Nick in his sleep.

Shy Turtle by River and Hannah May 4, 2009

turtle head poking out 

To have an extreme urge to defecate, so much so that feces may already be spreading the anus and attempting to escape.

Hold up man, I need to visit the crapper, I've got a turtle head poking out.

turtle head poking out by Tommy November 19, 2003

turtle-heading 

(verb – present participle) The act of experiencing the summit of a crusty turd protruding from your sphincter (a turtle head); to really need a crap

Onlooker: "Why are you walking so strangely?"
Protagonist: "I'm turtle-heading, if I don't find a toilet soon I'm going to purge all over my pants."

turtle-heading by Don de Mookster March 4, 2009

turtle test 

A turtle test is when you're not sure if you need to fart or shit, so you relax your butthole and push a little, and if a turtle's head peeks out, you clench your ass so you don't shit yourself. That is a "positive" turtle test. A "negative" is when a fart comes out.

Dude, pull over, I've gotta take a shit.

No way Bro, can't you just fart or something?

I just did a turtle test Dude, and it was positive. Pull over before I shit in your car.

turtle test by Otto Parts December 12, 2012