Mr. Vandemar is a character from the novel Neverwhere by Neil Gaiman. He is depicted as a sinister and menacing figure, often working alongside his partner, Mr. Croup. Together, they serve as antagonists in the story, pursuing the protagonist, Richard Mayhew. Vandemar is characterized by his cold demeanor and a penchant for violence. He is described as having a tall, gaunt appearance, which adds to his unsettling presence. His role in the narrative highlights themes of danger and the darker aspects of the London Below world, where he operates.