Shambuka

Shambuka (Sanskrit śambūka) is, in Hindu mythology, a character in the Adhyatma Ramayana version of Ramayana. According to that version, Shambuka, a shudra ascetic, was slayed by Rama for attempting to perform penance in violation of dharma, the bad karma resulting from which caused the death of a Brahmana's son. It is believed that Shambuka was beheaded in a hill at Ramtek, near Nagpur in Maharashtra.

Read more about Shambuka:  Source of The Story, Story, Criticism and Apologetics