Halon Oni (ハロンオニ) is a character of Bobobo-bo Bo-bobo. He is called Maloney Oni in the dub. He is the first of the Reverse Maruhage Empire's Four Heavenly Kings. Halon Oni is a boy with a demonic tail who is a member of the Reverse Maruhage Empire, as well as part of their Four Heavenly Kings. He has an uncanny resemblance to Heppokomaru in appearance. However, he is much more sadistic in personality, and appears to be slightly shorter than Heppokomaru. Halon has a demonic tail that can vastly increase the size of his opponents. He works with a large penguin-like creature called Slim.