Roscuro is a fictional character from the novel "The Tale of Despereaux" by Kate DiCamillo. He is a rat who lives in the dark, contrasting with the light-loving mouse, Despereaux. Roscuro's desire to experience light leads him to the human world, where he becomes entangled in a series of events that challenge his identity and morality. Roscuro's character embodies themes of darkness and light, representing the struggle between good and evil. His journey explores the complexities of friendship, forgiveness, and the consequences of one's choices, making him a pivotal figure in the story's moral landscape.