This clip, called The Duel, is based loosely on a 2006 animated short called...The Duel. Only this time it's in LEGO and shot in stop-motion, which makes it three minutes of your time well spent.

The animation was done by Namchild, who says that no CGI was used whatsoever, and that only PhotoShop was employed to edit out the wires necessary for the hot ninja action.