Roxas is sent to collect hearts at Olympus Coliseum, where Phil has him enter the arena to take out the Clay Armor. While fighting the Clay Armor, Roxas sees a brief memory of Sora fighting a horde of Soldier Heartless at the Coliseum.
A Clay Armor has a very large, round body that is almost entirely covered in armor. Its head is very small, pitch-black, and has a jagged mouth, glowing yellow eyes, and short, orange horns. It wears gold boots and large, gold and red gauntlets. The armor around its neck is gold, its breastplate is silver and light green, and the armor on its lower body is brown with a black, zig-zagging line around its abdomen. Its Heartless emblem is in the middle of its belly, just below its breastplate.
The Clay Armor's name references the Heartless's ability to use Earth-based attacks. The name also highlights the thick armor plating adorning the Heartless's body.
At the start of the battle, jump to avoid the shockwave that the Heartless boss summons when it leaps into the air. It may also cause a wave of energy to ripple across the field in a straight path, something easily avoidable. In this battle, the player should aim for the head of the enemy, as the body part of the enemy is invulnerable. Always watch for its movements; when the Clay Armor stops moving, it is about to attack. Should you be hit, you will face a great amount of damage from the Clay Armor's side-to-side slap attack. Should your HP fall into the "Alarm Zone", do not hesitate to use a Limit Break, though back away once the Clay Armor prepares to attack again. It is recommended that Block, Potions, Ethers, Cure, and Thunder panels be brought into this battle. Simply attack until the beast falls, and seize the opportunity to deal a slightly greater amount of damage on its head. You can attack the head before it falls by jumping, but most attacks will be deflected.