"殺人鬼" (satsujinki) is a Japanese term that translates to "murderer" or "killer." It refers to a person who intentionally takes the life of another human being. This term can apply to various contexts, including criminal cases, fictional stories, and psychological studies. In popular culture, "殺人鬼" is often depicted in movies, books, and anime, where characters may embody this role as antagonists. These portrayals can explore themes of morality, justice, and the human psyche, often drawing on real-life cases or historical figures, such as 連続殺人犯 (serial killers) or 犯罪心理学 (criminal psychology).