Tretista Kelverian (トレテスタ・ケルベリアン Toretesuta Keruberian) is a boss in Mega Man Zero 3. He is a Mutos Reploid designed after Cerberus, the three-headed hellhound. He is the Chief Judge of the Eight Gentle Judges, combining three independent thought circuits to reach fair judgements, and also serves as the Dark Judge (冥闇審官 Meian Shinkan).