Kzin are a fictional alien species from the Known Space universe created by author Larry Niven. They are characterized by their feline appearance, resembling large, intelligent cats, and are known for their warrior culture and aggressive nature. Kzin society values strength and combat prowess, often engaging in conflicts with other species. The Kzin first appeared in Niven's short story "The Warriors," published in 1967. They are notable for their interactions with humans, particularly through the character Louis Wu and the Ringworld series. Their complex society and history contribute to the rich tapestry of the Known Space setting.