There are dozens of ethnic minority groups in China have their own folklore: much of which contains valuable historical and cultural information as well as many unique myths.
Historic Chinese Legends, Tales and Idioms
Historic Chinese Legends, Tales and Idioms » Lang Tun Hu Yan
This video concerns one of the stories from the very famous Chinese novel, "Journey to the West." It informs us from where the idiom, "to wolf down your food," originates.