The animal known for its colorful tail is the peacock, specifically the male Indian peacock or peafowl. This bird is famous for its extravagant plumage, featuring vibrant colors and intricate patterns. The tail feathers, or "train," can fan out and include eye-like markings that are used during courtship displays to attract potential mates. The peacock's display is not only a showcase of beauty but also a demonstration of the male's health and genetic fitness, as brighter and larger tails can indicate better overall condition. This remarkable feature makes peacocks one of the most visually stunning birds in the animal kingdom.