Echidna, often referred to as the Witch of Greed, is a prominent character in the anime series 'Re: Zero kara Hajimeru Isekai Seikatsu'. She is known for her insatiable curiosity and desire for knowledge, often using her vast intellect to manipulate others to achieve her goals. Echidna is characterized by her striking white hair and dark attire, symbolizing her enigmatic nature. Her role in the series is complex; she acts as both a guide and a potential antagonist to the protagonist, Subaru, offering insights and challenges that test his resolve and understanding of the world.