The preternaturally strong, heavily armored Gaidora (ガイドーラ Gaidōra) is one of the Four Oni Predacons, remaining on Earth even after the Autobot-Decepticon war moved on. He has three horns, which is of significance to the Four Oni, if no one else.
At some point, Bakudora, Budora, Gaidora, and Judora entered stasis underground near Mount Fuji where the Demon Emperor Dragotron was buried. After a boy unknowingly unearthed Dragotron's head, the Emperor summoned his four servants to awaken from their sleep. Budora and Gaidora set out to find a Legendisc. Finding it in the ownership of Isami Tatewaki's grandfather, they attacked and threatened the safety of bystanders till Isami handed over the Legendisc. Fortunately, the Legendisc summoned the Swordbot Samurai Team in response to Isami's desperation. Despite Gaidora summoning the combining Goradora Jaki troops, Budora and Gaidora were forced to retreat against the power of the Swordbots' combinations.
Teaming up with Judora, Gaidora traveled back to try and obtain the Legendisc possessed by Kotarō Fūma, only for the ninja to make off through the trees as soon as the pair arrived. Encountering Tobio Fūma and the Swordbot Shinobi Team, the two Predacons summoned the Jaki and let them do the fighting. Unfortunately the Autobots triumphed and struck at the Predacons, sending them back to present day. Discover! The Legendiscs!
Gaidora and Judora were wondering how long Dragotron was going to remain asleep, until energy from their leader suddenly powered up Gaidora. The pair subsequently time traveled again, this time attempting to grab the Legendisc carried by Benkei Musashibō, only to find that Isami Tatewaki and the Swordbot Samurai Team had already beaten them there. Judora summoned the Jaki, and when they proved ineffective on their own, Gaidora absorbed their power, growing to immense size and battering the Autobots around. It wasn't until Isami gained possession of the Legendisc that the Autobots were able to combine and unleash sufficient attacks on Gaidora to defeat him and return him to normal size. The two Predacons returned to the present when the Autobots struck at them. The pair returned empty-handed to the cave under Mount Fuji, only for Dragotron to explosively appear before them.
The two Predacons located Isami and his Swordbot team shortly after the Autobots returned from the past having retrieved a second Legendisc. Dragotron soon joined them and the three Predacons attacked the Autobot team. Judora and Gaidora were knocked aside by Optimus Exprime as he arrived, and though Dragotron powered up the pair, causing them to grow in size, they only managed to hit each other while swiping at Optimus, then Optimus turned into a dragon and wiped the floor with them both. While Dragotron kept the Autobots busy, Judora grabbed Isami and the two Legendiscs he was carrying, and he and Gaidora headed for Mount Fuji. Later, during the battle between Dragotron and the Autobots at Mount Fuji, the Predacon summoned the Four Oni, and to their surprise absorbed them to add their power to his own. This still wasn't enough to prevent Dragotron's and the others eventual defeat and reimprisonment.
- Gaidora's name is based on "Supernatural Dragon" (怪・ドラ kai - dora), as demonstrated in his function of "Supernatural Strength Oni" (怪力鬼 Kairikiki).