The Samurai Mech was a large robot used by Samurai X to protect Ninjago from Serpentine threats. This advanced mech was equipped with a jet pack that allows it to fly, a detachable left fist, a large katana, a net for capturing enemies, and multiple projectile weapons. Later, it was modified to incorporate a seat on its shoulder, allowing a second person to ride the mech.
The Mech was eventually transformed to the Mech-enstein.
Upon reaching the Constrictai Tomb in the Mountain of a Million Steps, Kai and Nya revealed that they reconfigured the Samurai Mech's left arm and added a seat so Sensei Wu could join them in the battle. The mech was confiscated and chained up with the Golden Weapons, but used in the ensuing battle after Lloyd freed them.
The Samurai Mech was part of the Ninja exhibit at the Ninjago Museum of History.