Legend has it that before the God of the Northern Heavens died. he cut open his own body and took out his stomach and intestines. His intestines became a snake and his stomach became a turtle. Erroneously, butchers adopted him as their patron saint, and Taiwan now has many temples devoted to him.
相傳玄天上帝死前剝開自己身體，取出腸、胃，腸化成蛇，胃變成龜，最後被附會成為今天屠伕祭祀的對象，台灣也有不少玄天上帝廟。