It's one of the most interesting animated films I have seen recently, and it's called Aachi and Ssipak. Wikipedia has a semi-accurate summation of the plot:
Wikipedia wrote:Sometime in the future, mankind has depleted all energy and fuel sources, however they have somehow engineered a way to use human excrement as fuel. To reward production, the government hands out extremely addictive, popsicle-like "Juicybars", which in turn also act as a laxative. Aachi and Ssipak are street hoodlums who struggle to survive by trading black market Juicybars. Through a chain of events involving their porn-director acquaintance Jimmy the Freak, they meet wannabe-actress Beautiful, whose defecations are rewarded by exceptional quantities of Juicybars. For that reason, Beautiful is also wanted by the violent blue mutants known as the Diaper Gang (led by the Diaper King), the police (most notably the cyborg police officer Geko), and others.
If you're going to watch it on YouTube, be warned that Part Two is actually Part Three and vice versa. Also on most of the videos the audio lags behind the video and subs by as much as five seconds.