Uma is a mysterious and disfigured character who appears in The Witcher series. He is initially discovered as a grotesque, simple-minded stablehand, but his true identity is key to the story. Through a magical curse, Uma's real self is hidden, and Geralt of Rivia takes it upon himself to unravel the mystery. Uma plays a crucial role in the plot, serving as the vessel for an important character, which drives a significant part of the narrative.