The Serpents of Kilbane were a Chaos Space Marine warband affiliated with the Black Legion, led by the infamous Chaos Champion Thyraxeus Kilbane. The warband was fairly small, usually numbering less than one hundred strong and typically operating alongside other Chaos forces. However, all members of the Warband were seasoned veterans of The Long War, harboring intense, bitter hatred for the False Emperor and His followers. Due to Kilbane's especially intense hatred of Imperial Space Marines, the Serpents of Kilbane had a tendency to harass and even pursue Space Marine chapters operating in various warzones across the galaxy, particularly in the Segmentum Obscurus. The Serpents of Kilbane also made heavy use of terror tactics, for their hatred of the False Emperor's slaves knew no exception, and thus they would maim, burn, rape, and slaughter noncombatants with the very same ferocity as they would the ranks of the Astra Militarum or the warriors of the Adeptus Astartes.