Krell was a QuchHa' Klingon male serving in the Klingon Defense Force in the 23rd century. In 2267, Krell was dispatched to the planet Neural on a mission to upset the balance of power against tribal leader Tyree, by supplying one of his rivals with the "advanced technology" of flintlock weapons. Krell eventually gained the support of Apella after Krell promised him that if he cooperated with the Klingons, then he would become leader of the planet, and in turn, Krell would establish a puppet government and form an alliance with the Klingon Empire. Unfortunately, Krell's plot was later foiled by Captain James T. Kirk and the crew of the USS Enterprise who supplied Tyree's tribe with similar weaponry. (TOS episode & novelization: A Private Little War; WizKids module: Attack Wing)