A sweet, kind, and loyal Autobot to her friends, Arcee is also a merciless, lethal warrior to her enemies. Arcee's intelligence, quick wit, and coolness under fire make her invaluable to the Autobot cause. She is very protective of the young human, Daniel Witwicky, and is sometimes a bit overly protective. She is also concerned with the welfare of Hot Rod, though it is unclear if these feelings are signs of interest or just friendly affection.

Blurr is the fastest Autobot on land. He's a close descendent to a thoroughbred Cybertronic race horse, and a superior messenger. He can quickly whisk information from one place to another. In robot mode, he carries an electro-laser that reverses the polarity of an enemy robot's microcircuts and leaves them motionless. Range: 10 miles. In vehicular mode, he can travel faster than the speed of sound, leaving a blurred image in his trail.

Hot Rod is an all-American-boy Autobot. He's a typical adolescent who dreams of being heroic and important. He tends to follow rules too closely. Although he means well, Hot Rod's impulsive actions often get him into trouble. He carries two photon lasers that temporarily electromagnetize an enemy robot's microcircuts. Speed: 120mph. Range: 4 miles. He can be hotheaded, but he's always a well meaning, admirable lad and a brave and honorable fighter.

Chivalrous, well-skilled in the art of war, Kranix is a friar warrior and the last survivor of the planet Lithone. Like all Lithones, Kranix possesses a high perceptage of emotional circuits in his computer brain. The burden of being the last survivor of his home planet Lithone has taken a huge toll on Kranix. A melancholy cloud seems to hang over him. Some say he has lost all purpose in life and can now achieve peace only in a warrior's death in the forefront of battle.

Kup is an old veteran warhorse with a thousand tall tales from his ten thousand adventures. He has a motto or word of advice for any situation and he's as brave and loyal as they come. Kup sees himself as a seasoned campaigner with more knowledge and experience to share. Other Autobots aren't always receptive to his advice.

Optimus Prime leads the Autobots in their battle against the Decepticons, and he is the only Autobot with the strength and courage to combat Megatron and his militant band of followers. Determined to one day reclaim his homeworld of Cybertron from his enemies, he is even more concerned with the welfare of the life forms of planet Earth, and will stop at nothing to prevent Megatron from conquering the Autobot City complex he has constructed to protect the humans. But will his determination and resolve be enough to defeat the devious and merciless Megatron? Through the power and wisdom given to him by the Autobot Matrix of Leadership, Optimus senses the coming of a hero who will lead the Autobots through their "darkest hour."

Rodimus Prime is the mature, transformed persona of Hot Rod, and possesses the power and inherent wisdom that resides within the Autobot Matrix of Leadership. He is a vanguard for the Autobot ranks. He speaks with the savvy of seasoned veteran, and possesses acute military prowess. Despite these enhancement, he remains Hot Rod underneath, and he can still be hot-headed at times. Like Hot Rod, he has a tendency to act first and ask questions later. While before he was seen as just a rebellious youth, now the Autobots turn to him for leadership. It is a responsibility he is not sure he can handle.

A wise-cracking, sharp witted adventurer, Springer is a powerful Autobot fighter with a massive physique and an easy-going manner. Possesses incredible "springing" power in his legs. Travels long distances with pogo-like motion. In robot mode, carries a laser that produces giant wind tunnels. Helicopter blade transforms into a light saber that can cut through concrete. Optimistic and good humored.

Ultra Magnus is all soldier. Most comfortable when carrying out Optimus Prime's orders. Possesses magnificent fighting skills, courage, and a gift for battlefield improvisation. Uncomfortable in the mantle of leadership, but presents strong profile as a commander. Resolute, fair, and courageous beyond reproach. Ever ready to sacrifice himself for the good of men and mission.

Wreck-Gar leads the Junkions, a race of junk robots. He's made of rusted scraps, chassis bits, manifold parts, and dented odds and ends. A little scatterbrained, he speaks in odd-ryming, pieced-together sentences. His words are a junkyard collection of broadcast fragments from T.V. commercials and radio jingles.

Galvatron was once the Decepticon leader Megatron, and was transformed into a more powerful robot by Unicron. Galvatron is Megatron to he ultimate degree; more evil, more powerful, and even less subject to emotion or decency. Possesses enough strength to pulverize an enemy into scrap metal. Through the powers of Unicron, Galvatron's own powers are augmented continuously, boosting his arrogance enough that he plots against own his allies, thus only weakening his position. He has also become the unwilling servant of Unicron, and Galvatron hates answering to anyone but himself. His new enemy is not an Autobot, but the planet-sized monster with whom he has collaborated. Will he choose to make allies with his Autobot foes and lose his newly gained power, or remain Unicron's servant forever and destroy the Autobot Matrix, as Unicron would have him do?

Megatron combines brute strength, military cunning, ruthlessness and terror. After conquering his homeworld of Cybertron from the Autobots, he plans to possess all Earth resources. He is incredibly powerful and intelligent, and he fires a nuclear-charged fusion cannon, which can link up interdimensionally to a black hole and draw antimatter from it for use as a weapon. Megatron has no known weakness.

As cruel as a weasel toying with its prey and as persistent as a bloodhound on the trail of a fugitive, the Quintessons are composed of Guards, Gatekeepers, and one five-headed Judge. They are the cruel masters of the endless legions of Sharkticons which carry out the Quintessons' verdict. Guilty or innocent, the verdict is always the same - death.

Seeks to replace Megatron as leader. Ruthless, cold-blooded, cruel... considers himself the most sophisticated and handsome of Decepticons. Believes Decepticons should rely more on guile and speed rather than brute force to defeat Autobots. Fastest flyer of group, can reach Mach 2.8 and an altitude of 52 miles. Shoots cluster bombs and null-rays which disrupts the flow of electricity. Very good at what he does, but sometimes overrates himself.

Unicron is the most massive and deadly of all the Transformers. The size of a large planet, Unicron derives sustenance from munching planets, moons, and even stars, thus making him larger and increasing both his power and his appetite. When it serves his interest, he has been known to make pacts with lesser beings, offering them stronger bodies and greater powers in exchange for total allegiance. In addition to his ability to transform into a gigantic robot, Unicron is also capable of observing all that goes on in the universe. Unicron fears only one thing - the Autobot Matrix of Leadership.

Daniel is the offspring of Spike Witwicky and his wife Carly (who does not appear in the movie but is featured in the TV series). He is a "classic twelve year old American boy," who dreams of being reunited with his father, who is involved in the war to regain Cybertron. Daniel's fate changes when the Decepticons attack his homeworld of Earth, and he soon finds himself in the middle of an adventure that takes him through the far reaches of space, in an attempt to rescue his father from the "monster planet" Unicron.

Spike Witwicky, the son of "Sparkplug" Witwicky, is a long-time friend of the Autobots since he met them during his teenage years. He is now 35 years old, has been married to his sweetheart Carly, and has a son, Daniel. Armed with a powerful high-tech "exo-suit," he is stationed on Cybertron's Moon Base 2 with his friend Bumblebee, helping the Autobots reclaim their homeworld of Cybertron.