Momonjii is a human-like yokai who appears as an antagonist in the GeGeGe no Kitaro franchise. He is a devious and cunning figure who specializes in deception and conning others. His most notable role is in the storyline known as The Great Yokai Trial, where he disguises himself as a fake Kitaro and commits various evil deeds, framing the real Kitaro for his crimes. This leads to Kitaro being falsely accused and put on trial before the Great Tengu's Yokai Court. Momonjii's motivations are rooted in malice and a desire to cause chaos, often targeting innocent people and using trickery to achieve his ends. He possesses abilities similar to Kitaro, including the power to shoot his nose hair like sharp needles or create bubbles from his nose that can form lifelike dolls of humans. These abilities aid him in his schemes of impersonation and deception. He has no known relationships beyond being an enemy to Kitaro and his allies, and he appears as a recurring threat in various adaptations. The character does not undergo significant development, typically remaining a static villain who uses cunning to disrupt the peace between humans and yokai.