Ratchet is the main protagonist of the Ratchet & Clank franchise.
Despite being the main protagonist of the franchise, he started off as an anti-hero and the protagonist villain in the first game as he was very selfish, arrogant, and self-absorbed and only focused on his goals rather than helping other people to the point where Clank, his robotic sidekick had to talk him into helping other planets.
He almost crosses the Moral Event Horizon when he was about to leave a commando to die in a war until Clank talked him into helping.
After defeating Qwark he saw a city destroyed by Drek and became a much nicer person.