Leader of the Autobots. While he is known for having a prominent chin, his toy iterations are often sculpted with a relatively balanced one. He transforms into a fire truck—or so it is said, but since the rear section of the vehicle is entirely absent and he has been seen towing a semi-trailer in some episodes, he is effectively a tractor-trailer. His weaponry includes the telescopic Ultra Axe and the wrist-mounted Ultra Anchor, along with various equipment like throwing weapons and fire suppressant.

The youngest member of Optimus's squad, transforming into a small undercover police car. He has a complex about his short stature, but his friendly personality makes it easy for him to bond with humans, especially Sari. He is the most upbeat and talkative member of the team, often acting like a jokester, but when things get serious, he faces enemies more bravely than anyone. He takes great pride in his speed.

Appears as an elderly Autobot. A veteran medic with a burly physique and facial plating reminiscent of stubble, giving him a distinct 'grumpy old man' vibe. As the oldest member of the squad, he supports the young and inexperienced Optimus in many ways. He shares a dark history with Lockdown, who stole his EMP generator during the war, leaving Ratchet with a broken right horn.

An Autobot who transforms into an armored truck. His protruding lower jaw is more like a mask or cover, with his actual mouth located further back. Despite his hulking frame, he has a kind and sensitive heart. While he is generally clumsy and prone to breaking things around him, he is surprisingly dexterous when it comes to fine work. He possesses a hidden talent as an engineer and machine enthusiast, particularly regarding space bridge construction. Interestingly, when his instructor Sentinel Prime asked his recruits about their goals, Bulkhead's honest answer that he wanted to be a 'space bridge technician' was met with mockery.

An Autobot cyber-ninja and scout who transforms into a police motorcycle. He is a deep lover of Earth's nature, going so far as to keep a large tree, bonsai, and animal posters in his room at the base. While usually calm and collected, he showed some signs of 'edgy' behavior early on. According to previews, he likes salt ramen. He is a versatile fighter using shuriken-like 'Soma Edges,' holograms for decoys and stealth, and even a form of psychokinesis through meditation.

The 8-year-old daughter of Professor Isaac Sumdac. A mischievous troublemaker whose bright and proactive nature allowed her to quickly bond with the Autobots, despite their initial tendency to look down on organic life (though Optimus's team was already quite open-minded). Her initiative and creativity often lead to trouble, but she saves the Autobots from crisis just as frequently. For some reason, the AllSpark entrusted her with its Key, allowing her to tap into its power.

A very mild-mannered man and a devoted father who dotes on his daughter, Sari. While he is a brilliant scientist and engineer, he is also quite gullible and easily deceived. He is not Sari's biological father; Sari is actually a 'human-Transformer hybrid' born when Isaac accidentally touched a Transformer 'protoform' that had found its way into his lab, causing his DNA to be encoded into it. He kept this secret for years, raising her as his own daughter.

The leader of the Decepticons, characterized by a powerful, gravelly voice. He initially transforms into a Cybertronian jet, and after his resurrection, into a twin-rotor attack helicopter. He refers to himself with a formal, regal 'I' (Ware), though he used a more arrogant 'I' (Ore-sama) early on. He is equipped with a fusion cannon on his right arm and two large 'Meganium Swords' formed from his helicopter rotors. He attacked the Autobot ship in the past but was betrayed by a subordinate, losing an arm and falling to Earth as a severed head.

The Decepticon Air Commander, a cringeworthy narcissist who considers himself the 'main character' and a 'handsome guy.' He transforms into a forward-swept wing fighter jet. His personality is exceptionally devious and cowardly. At the start of the story, he planted a bomb on Megatron to assassinate him while he was attacking the Autobots. However, Megatron survived, and when Starscream tried to finish him off while he was weakened, his treachery was exposed, leading to his execution by the resurrected Megatron.