The Rexoskell (Japanese: トゥルドゥール, Turudūru) is a Mission Exclusive Secondary Boss in Xenoblade Chronicles X. This Skell enemy belongs to a unique subcategory in the Enemy Index. It is piloted by ER001: Emeroa and is fought twice during Definian Downfall, first at level 50 at the Ganglion Antropolis in Cauldros, then at level 54 on the Emerian Battlegrounds. After completing Definian Downfall, the Rexoskell can be battled again in the Gone Berserk Time Attack Mission, and a level 40 version can be fought in the Corporate Espionage Squad Mission.