A Poof Ninja is another term for stupid looking female that jus woke up, and is extremely pissed off at the world. She has ninjaabilities cause she is a karate master, and knows many major pressure points on the human body. The "poof" is for the marshmallow "poofness" her face looks like after having 3 hrs sleep cause of all the wild sex from the previous night.
Evan: Hey that chick sure looks like a poof ninja.
Ran: Hey poof ninja, wanna go get a facelift to fix ur face.