The Roto Jet is a small bomber based off a type of attack plane created in Karlof's homeland, Metalonia. It was said to have enough firepower to take out an entire army. During the Tournament of Elements, the Elemental Masters, who were being forced to work in Chen's Noodle Factory, designed a "noodle-making machine," which was really a Roto Jet. The group used the jet to escape the factory, which would soon allow them to disrupt Chen's ceremony.
After the Anacondrai Cultists transformed into fake Anacondrai, they departed from Chen's Island with Bladecopters, while Chen stole the Roto Jet and flew it off himself. During the second Serpentine War, Chen flew the Roto Jet during the battle at the Corridor of Elders. It is unknown what happened to the jet following the battle, as Chen's army was banished to the Cursed Realm.
While brainstorming ideas to break themselves out of the Noodle Factory, Karlof mentioned how he used to work on Roto Jets and suggested they build one out of machine parts. Although Cole was skeptical about how a jet would be any use underground, the other prisoners agreed and began finding parts, while Karlof and Zane created a blueprint.
By the time the remaining Elemental Masters were taken to the Noodle Factory, the Roto Jet was nearly finished, constructed under the guise of it being a noodle machine. Jay began working on the vehicle as well and by the time Chen defeated the Green Ninja, the rotating barrel was operational. Upon receiving an large order of noodles for the banquet, Zugu decided to check on the "noodle maker," only to find the Roto Jet. Cole quickly hoped in and began firing at incoming cultists. With help from the other Elemental Masters pushing the jet, they managed to escape the factory.
After the Cultists captured Pythor and made the transformation spell permanent, they set off into Ninjago. As Chen taunted Pythor, he departed via the Roto Jet along with his army.
Later, he had several of his followers carry the Roto Jet into the Corridor of Elders, with Chen sitting inside of it. When the battle at the Corridor commenced, Chen flew the Roto Jet, eventually abandoning it as his army overwhelmed the Elemental Masters. As he stepped out of the cockpit, Chen was confronted by his daughter Skylor.
After the Anacondrai generals were freed from the Cursed Realm, they banished Chen and his army there. The status of the Roto Jet following the battle is unknown, although it is possible the Ninja took it back and stored it away.
Shadow of Ronin (non-canon)
- Just like the Earth Driller, the set version is called Cole's Boulder Blaster, but it wasn't ever specifically Cole's.