Zen(ゼン Zen) are two Mechasaurs from Episode 18 of Getter Robo. The first one is called Zen-1(ゼン1号 Zen 1-gō) and the second one is called Zen-2(ゼン2号 Zen 2-gō)
Two of the Mechasaurs mostly have the same appearance: They are both have the appearance of a bipedal dinosaur with a brown scaly hide and a dark yellow underbelly. Each one is wearing a metal plated breastplate while the neck, the back of the head, and lower jaw are mechanical in appearance, leaving the upper jaw and face the only parts of the head organic. The only difference between the two is that Zen-1 has mechanical hands and is equipped with two yellow wings on the back. Zen-2 has no wings and only it’s left hand is mechanical while it’s right hand is replaced with a spiral arm with four blades sticking out.
Chief Galeli shows Emperor Gore a multi-dimension bomb made to look like a screw. Emperor Gore gets one of General Bat’s men, Zenki, to implant the bomb at the Saotome Studio. Chief Galeli presents Zenki the latest Mechasaurus, Zen-1. However, Zenki doesn’t like how the Mechasaurus is made for combat in the air, so he has another Zen made from an egg combined with Tyrannosaurus and Stegosaurus DNA to be created for land combat. While he waits for Zen-2 to be done, Zenki goes ahead and takes Zen-1 out to fight Getter Robo and to find out by relations it has with the Saotome Plant. When the Saotome Plant gets a signal of the Mechasaurus coming toward them, Professor Saotome sends out Ryoma, Hayato, Musashi, and Michi in their vehicles. As they fly toward the Mechasaurus, Ryoma combines the Getter Machines into Getter-1. Zen-1 fires a missile from it’s fore head, but it gets destroyed by Getter Robo’s Getter Beam. Zen-1 then flies past Getter Robo and heads toward the Saotome Plant. Zenki gets Zen-1 to fire it’s missiles at the Saotome Plant, but fortunately the plant has it’s shields up. Getter Robot make it time and uses Getter Tomahawk to slice of Zen-1’s right wing. Then, Getter Robo uses Getter Beam to shoot down Zen-1, letting fall down into a canyon where it explodes upon impact. Zenki, however, escapes before the Mechasaurus hits the ground.
Zen-2 was incubated from an egg combine s with Tyrannosaurus and Stegosaurus DNA. It was created opunder orders by Zenki, who preferred a Mechasaurus who can fight on land. Once Zen-2 was hatched and is instantly grown into a mature dinosaur, it is taken away to be modified. Later, after the destruction of Zen-1 and after Zenki successfully destroys the protector for the Saotome Plant as well as implanting the multi-dimension bomb in Getter Eagle, Zen-2 is released. Zenki gets Zen-2 to arrive at the Saotome Plant and the Mechasaurus starts wrecking the place with it’s forehead missiles and Spiral Arm. With the bomb in Getter Eagle, Ryoma, Hayato, and Musashi cannot combine the Getter Machines. After a while, Zenki decides to head off with Zen-2, leaving the Saotome Plant in wreckage. Later, Zenki betrays General Bat in order to get into a higher position, so Emperor Gore dumps him into lava and sends Zen-2 out to destroy the city. Ryoma heads out with Getter Machines by himself to fight against Zen-2 after Professor Saotome planted an anti-explode device so the bomb won’t explode immediately. When Ryoma arrives at the city with the Getter Machines combined into Getter-1, hecarefully tries to cut around the screw bomb in Getter Eagle cockpit. However, without Musashi and Hayato, Zen-2 is able beat up Getter Robo. Emperor Gore command Zen-2 to use it’s Spiral Arm, so the Mechasaurus uses it to cut off Getter Robo’s left arm. Despite Ryoma trying to fight back, Zen-2 knocks Getter Robo down and continues it’s destruction. Fortunately, Hayato and Musashi make it in time to help out Ryoma, where he discovers that Zen-2’s attack loosened the cut off piece around the bomb. Ryoma gets Getter Robo back up and throws the multi-dimension bomb at Zen-2’s head, knocking it down and destroy it’s forehead missiles. Ryoma tells Hayato to change into Getter-2 so they can destroy Zen-2’s Spirla Arm, so Hayato combines the Getter Machines from Getter-1 to Getter-2 and destroys the Spiral Arm with Dril Arm. Ryoma combines the Getter Machines back to Getter-1 where Getter Robo uses Getter Tomahawk to slice Zen-2 in half from down the middle. The two halves fall to the ground and explode, killing off the Mechasaurus.
Flight: Zen-1 has wings that allow it to fly through the air.
Forehead Missiles: Zen-1 can shoot missiles from it’s forehead.
Forehead Missiles: Just like it’s predecessor, Zen-2 can shoot missiles from it’s forehead.Spiral Arm: Zen-2 has a set of four blades on it’s right arm where it can spin into a spiral.