turtling

To sneak up behind someone wearing a hoodie, then inverting the hood on said hoodie, thus making it appear as though the person now has a turtle shell on their back.
This can then be accompanied with shouts of 'TURTLED! TURTLED!' at the victim while simulating a turtle shell on your own back.

*sneaks up behind and flips hood*

Leah: HAH TURTLED
Talon: what does that mean?
Leah: Turtling is when I flipped your hood and gave you a turtle shell!