Chochin Obake
See the painting process and hear the legend on Youtube here
Legends in Japan, especially Yokai are often influenced by Shintoism and the belief that all things have a spirit. It is through this that the Chochin Obake finds itself. It is believed that once an object has survived 99 years it develops a spirit. In the case of these lanterns made from bamboo and paper they would eventually split, forming what appears to be a gaping mouth. Visualize these blowing and flickering in the wind and one can image where the folklore started.
In pictures and tattoo they are shown with large mouths and two eyes, hair and at times a long tongue. Sometimes they are also depicted with arm and even legs. These are harmless yokai and they prefer to scare people than harm them. They stick their tongues out and roll their eyes and laugh loudly to scare passers -by.