Demon is a minor villain in the Ginga Densetsu Weed manga.
He was a very strong dog who had many followers. One day, he challenged Gin in a fight, cause he'd killed one of Gin's messenger. Gin wasn't told how many followers Demon had, so he only brought Tesshin with him. Demon took this as an insult and charged at Gin. Gin threw him in the air and he landed heavily on the ground. The blow killed Demon easily.