|This article is about a/an companion/ally in Engine Sentai Go-Onger.|
|"Bom-Bom! Gaiark detected."|
|―BOMPER alerts the Go-Ongers|
Bomper (ボンパー Bonpā) is a supporting character in Engine Sentai Go-Onger
Bomper is a pink navigation rabbit robot created by Jum-bowhale from the Machine World (though he originally planned to paint him violet and pink with green and blue polka dots), supporting the Go-ongers by creating their arsenal, performing maintenance on the Engines, and at the beginning of the eyecatch, he is served as the referee. Everything relating to Bomper involves the number 66. All of his dimensions are 66 cm, weighing 66 kg with a top speed of 66 km/h. As Bomper is from the Machine World, he ends his sentences with "Bom-Bom!" (ボンボン！ Bonbon!).
Bomper's name is an acronym for "Born-to Outerdimension and Mechanic x Pitcrew-type ENGINE-support Robot". Jum-bowhale tried to design him with colorful dots.
He remained with the Go-Ongers through their entire adventure and when Sosuke met the Shinkengers, .
On one occasion, Bomper ran away thinking that the Go-Ongers didn't want him around. But he was proven wrong and returned home.
While the Go-Ongers were trapped in Samurai World, Kegalesia accidentally separates her Kegalesia Soul (ケガレシアソウル, Kegareshia Sōru) from her body, with her soul set into BOMPER by the other Ministers to convert the robot into Bompelesia (ボンパレシア, Bonpareshia) so they can take advantage of the situation by setting a trap, giving him lipstick and eyelashes (and a female voice). However, Bomper manages to regain control of his true self and ejects the Kegalesia Soul prior to being reinstalled back in her body.
After the Great Legend War, surviving members of Gaiark attacked Gunman World. BOMPER fell out of a dimensional hole to Human World, landing in the Gokai Galleon. He introduced himself to the Gokaigers and brought them to Sosuke at a race track. BOMPER informed Sosuke and the Gokaigers that Gunman World was being terrorized by Barbaric Officer Chirakashizky, a surviving member of the Gaiark Clan and that Engines Speedor, Bus-on, and BearRV have already tried to stop him, but were defeated instead and lost their power. Sosuke asks the Gokaigers to help, but Captain Marvelous refused, claiming that they would not get anything from it, particularly after they have already received the Go-Ongers' greater power. Sosuke decided to go by himself, but after his various failed attempts to reach the hole, Captain Marvelous and the others appeared, and he said that he would give Sosuke a ride if he wanted. The group traveled to the Gunman World, where they save several of its denizens from a group of Ugatz.
They eventually catch up with Speedor, Bus-on, and BearRV, and learn that Speedor and BearRV have married and that they have a son: Engine Machalcon. However, Machalcon is a reckless troublemaker who spent his time racing around in the Machine World rather than helping out his parents. Their reunion is cut short by Chirakashizky who challenged the Gokaigers to a duel. Captain Marvelous accepted the duel, and despite resorting to dirty tricks, Chirakashizky was defeated by the Gokaigers. During their battle with the enlarged Chirakashizky, the Gokaigers tried to use the greater power of the Go-Ongers, but nothing happened. They decided to take him out with Hurricane GokaiOh. While the pirates confronted Sosuke about the reason why the greater power is not working, they were contacted by Pollution President Babatcheed, the new leader of Gaiark, who revealed that he merely used Chirakashizky to lure the Gokaigers into the Gunman World, and by sealing the wall between dimensions, the pirates were now unable to return to the Human World, leaving the way open for the Gaiark Clan to conquer it.
With no other option, the Gokaigers, Bomper, Sosuke, and the Engines head for Machine World to try and get Machalcon to help the Gokaigers get back to Earth. They challenge Machalcon to a race, with an incomplete GokaiOh successful able to tame Machalcon. Bomper was later there to see the Go-On GokaiOh defeat Babatcheed.
The BOMPER Soul is a toy-only item that was given away to attendees of the theatrical movie Engine Sentai Go-Onger: Boom Boom! Bang Bang! GekijōBang!!.
- His name is a reference to a car bumper.