Yiazmat, the Wyrm God, appears in both Final Fantasy XII and Final Fantasy XII: Revenant Wings. In FFXII, there are 45 optional side quests called Hunts, in which the player must defeat various monsters. These monsters are called Marks or Elite Marks. The quests are obtained either on notices found throughout the game or are received from the moogle, Montblanc. Yiazmat is the ultimate Elite Mark in the game.

1. Hit Points: 50,112,254
2. Weakness: Dark
3. Absorb: Holy
4. Location: Colosseum at Ridorana Cataract
5. Recommended Level: 80+
6. LP Gained: 255
7. Rewards: 30,000 gil, Godslayer's Badge

To gain access to the Yiazmat quest, the player must first complete all other Hunt quests and defeat Yiazmat's little brother, Hell Wyrm, in the Sochen Cave Palace. The Yiazmat battle is notorious, as it can take several hours to defeat him. It is possible to step away from the battle, heal up, and save your progress at a nearby Save Crystal. However, when you move out of his attack range and stay gone too long, Yiazmat will cast Regen. This should be dispelled before you leave. When his HP reaches 50%, all attacks on Yiazmat can do only a maximum of 6999 damage. When his HP gets really low, Yiazmat will cast Reflectga. Be careful not to cast Renew at this time, as it can heal Yiazmat to full.

One of the rewards for defeating Yiazmat is the Godslayer's Badge. It is needed, together with the Omega Badge and Lu Shang's Badge, to obtain Wyrmhero Blade. This is one of the strongest weapons in FFXII.

• 33 - Chickatrice, Cluckatrice
• 34 - Rocktoise
• 35 - Orthros
• 36 - Gil Snapper
• 37 - Trickster
• 38 - Antlion
• 39 - Carrot
• 40 – Gilgamesh with Enkidu
• 41 – Belito
• 42 - Behemoth King
• 43 - Ixion
• 44 - Shadowseer, Pandaemonium, Slyt, Fenrir, Phoenix