Idirans are a fictional alien species from the science fiction series "The Culture" by author Iain M. Banks. They are known for their warrior culture and strong sense of honor, often engaging in conflicts with other species, particularly the Culture itself. Idirans are characterized by their physical strength and resilience, making them formidable opponents in battle. The Idirans are a tri-partite species, meaning they have three distinct heads, each with its own personality and perspective. This unique biology influences their social structure and decision-making processes. Their complex relationship with the Culture highlights themes of conflict, morality, and the nature of civilization in Banks' works.