Optimus Prime is a fictional character created by the Transformers franchise. He is a Cybertronian, a fictional extraterrestrial species of sentient self-configuring modular robotic lifeforms (e.g.: cars and other objects), a synergistic blend of biological evolution and technological engineering. In almost every version of the mythos, Optimus is the leader of the Autobots, a faction of Transformers who are rivals of the Decepticons, another faction. He is defined by his strong moral character. He seems to have a naturalistic worldview and has said "Freedom is the right of all sentient beings".
Optimus on Wikipedia