Optimus Prime (TF 1988)

Optimus Prime is a character from the 1988 Transformers film. Peter Cullen reprises his role as the Autobot leader. In order to make the film more realistic, he transforms into a Mack fire truck instead of the cab over. As well, he has some white stripes on him from the fire truck parts. In fact, Infernocon, a Decepticon fire truck in the same film wishes to defeat the leader and take the Matrix of Leadership after Optimus's brother Megatron whatever Decepticon takes the Matrix first becomes leader. Optimus has believed that though he might be forced into defeating Megatron once and for all, he still believes about he war coming to an end.

Involvement in the film
During the war on Cybertron, Prime promised the Autobots that they would be rich of Energon resources in case anything happened. While they were successful in that, Starscream, Megatron's second-in-command, betrayed Megatron to take leadership, while Megatron got stuck when the starship began falling  apart, colliding with Autobot ship and knocking Prime out in the process, before the ship collided into an earth volcano. Millions of years later, human scientists discover the ship and it's crew, reviving the Autobots and Decepticons with mini-satellites only to cause a Decepticon attack. After Megatron told the plan to steal the Matrix, he confronted Prime (who was unaware of the plan) explaining that the Cybertronians can somewhat live again like millions of years ago, but told Optimus they will have to destroy most and get rid of the humans before he left off, leaving Prime alive and thinking, right before he left the Autobot ship the Ark scanning a fire truck as a vehicle mode. He then lead a pack of Autobots disguised as vehicles: Second in command Jazz, Ironhide, Ratchet, Bluestreak, Prowl, Wheeljack, Bumblebee, and Cliffjumper. The Decepticons then headed for an attack, forcing Prime to send Bumblebee to check on any problems. After the attacks, Prime is told that a human named Spike Witwicky was rescued in the process, and Prime told them to find the boy and protect him. It turns out successful only for someone to arrive, revealing it to be Decepticon scientist Shockwave, who reveals to Optimus the plan to steal the Matrix, but Prime uses enough energy to make a rough punch that kills Shockwave. However Shockwave before has kidnapped Bumblebee and Spike. After this, Prime contacts Bumblebee, aboard the Nemesis, to destroy the drones and rescue Spike. During the final battle, Optimus Prime battles with Megatron, and order to defeat his brother, Prime uses the Matrix's power which blasts the Decepticon to the ground. After Megatron awoke, Prime used the Matrix telling Megatron that "he (Megatron) wanted it" before using the matrix to smash Megatron's face which destroyed the head's circuitry, killing the Decepticon leader. After the battle, the Autobots arrived and listened to Prime's speech, as he told earth could become a new home for the Autobots after the fall of Cybertron.