Fictional ninja

Orochimaru (大蛇丸), featured in the Japanese folktale Jiraiya Gōketsu Monogatari, is the archenemy of the ninja Jiraiya. He was once named Yashagorō (夜叉五郎) and was one of Jiraiya's followers but was overtaken by serpent magic. Having changed his name to Orochimaru, he gained the ability to turn himself into a giant serpent. He attacked Jiraiya and Tsunade and defeated them with his venom, only for another follower to save the couple's lives afterwards. "The story, first recorded in 1806, was adapted into a mid-19th-century serialized novel and a kabuki drama, based on the first 10 installments, by Kawatake Mokuami, in 1852. In the 20th-century, the story was adapted in several films, in video games, and in a manga."