From Dragon Ball Encyclopedia, the ''Dragon Ball'' wiki
Moai (モアイ, Moai; FUNimation "King Moai") is the king of Planet Arlia. He is a cruel and ruthless dictator who imprisons Atla and all of the good Arlians, and holds battles between his guards in which the loser is fed to a giant Arlian, Yetti, who resides in The Pit.
Moai appeared in "Terror on Arlia". He took Atla's wife, Lemuria, from him to marry her. After Lesoy defeated Greger, Moai ordered the latter to be executed by being fed to Yetti and ignored Greger's pleas. When one of his soldiers revealed that Nappa and Vegeta had arrived on Planet Arlia and were captured, Moai ordered to have the Saiyans be brought to him, hoping to find entertainment, but to his surprise they escaped prison and killed all of the guards. Moai then ordered Lesoy to fight against the two. He promised them that he would give them anything if they won, though he doubted that they stood a chance. Vegeta killed Lesoy instantly and Moai refused to keep his word of giving them the planet and all of the Arlians' lives as they demanded and instead ordered his guards to kill the two Saiyans as punishment for their insolence. Nappa used his Volcano Explosion to wipe them all out and Moai, desperate and shocked, released Yetti from The Pit. He ordered the mighty Arlian to kill Nappa and Vegeta. When Nappa tore off one of Yetti's fingers and easily finished him off with a Bomber DX, Moai became horrified as his last trump card was vaporized. He ran away screaming in terror and hid behind his throne, but Vegeta shot a rock at him through his heart, killing the tyrant Arlian king once and for all.