ninjafy

1.when you do something ninja-like (most likely attacking in a ninja fashion) to someone completely unexpectedly.
2. also can be used as a threat. usually not very scary.
3. generally leads to the injury of the person doing the ninja-fying.

sophie : dont make me NINJAFY you!
kat : you are insane.

sophie : i tried to ninjafy him but it resulted in the breakage of my arms.