Zai(ザイ Zai ) is a Triceratops-Themed Mechasaurus from episode 1 and 2 of Getter Robo.
Zai was one of the three Mechasaurs to be sent out to the surface world by Emperor Gore. Zai, along side with the other two Mechasaurs, causes destruction on mankind. Later, after the destruction of Mechasaur Saki, Zai and the other two Mechasaur arrive and fight against Getter Robo. After Getter Robo gets away, Emperor Gore commands them to destroy the Satome Plant. After doing so, he calls the three Mechasaurs back. Later, Emperor Gore sends them back out again to cause more destruction. Zai was the first of the three Mechasaurs to face against Getter Robo. Hayato changes Getter Robo into Getter 2. After a small fight, Zai burrows into the ground. Getter 2 pursues Zai with it's Getter Drill. When Hayato locates Zai, he uses the Getter Drill to drill through the Mechasaur, destroying it.
Shield: Zai can use the folds around it's head to protect itself.
Missiles: Zai can flip open his front horns to fire missiles.
Burrowing: Using his horns like drills, Zai can burrow through the ground,