So last Sunday was the Annual Day of the Ninja! And what better way to celebrate than to put on your finest shinobi shozuoku, sharpen your throwing stars and go assassinate some warlords?

On second thought, that sounds kind of strenuous. And who wants to get blood all over his best ninja uniform, anyway?

So instead, we invite you to celebrate this arse-kicking holiday with some of the greatest ninja fails on the Internet. Keep reading for a hilarious dose of hi-YA!

If you're going to engage in nunchuck fighting, do yourself a favor and invest in lessons first. And a nut cup.

What this kid lacks in ninjutsu skills, he makes up for with his totally sweet hairdo. Watch his mullet ponytail fly at the 5:04 mark, when he debuts his two-sworded "dragon twister move."

Many say that breaking a stack of bricks with your bare hands requires little more than the power of mind over matter. We would argue that it also requires aim.

In all fairness, that branch didn't deserve to be roundhouse-kicked, anyway. The guy who's holding, on the other hand ...

This is what happens when you watch "The Karate Kid" one too many times. Sweep the leg, kid! Sweep the leg!