The Thirteenth Colossus is the thirteenth enemy fought by Wander in Shadow of the Colossus. Like the game's other Colossi, it is a large golem that appears to be at least partially constructed from stone. This Colossus takes the form of an enormous winged serpent that resides in an expansive desert to the southwest of the Shrine of Worship. It is the third snake-like Colossus after Hydrus and Dirge, as well as the second of the game's two flying enemies along with Avion. It is also the longest Colossus from head to tail, measuring over one hundred forty meters in length, and is remarkably docile compared to the game's other foes.
Players begin this battle by stepping onto one of the desert's larger ruins, triggering the Thirteenth Colossus' emergence from the sand. This unusual creature is kept aloft by its three gas bladders; by piercing each of them with arrows, Wander can reduce the Colossus' altitude and cause its wings to drag through the desert sands. Riding Agro alongside one of the creature's lowered wings allows the player to jump onto it at speed and begin climbing towards the three weak points on its elongated body. The Colossus will try to shake Wander off by squirming and barrel-rolling. Eventually it will cover its weak points with flaps before diving underneath the sand to dislodge the player, forcing Wander to repeat the process of mounting it again.