Cooler is the main antagonist of Dragon Ball Z: Cooler's Revenge and Dragon Ball Z: The Return of Cooler. He is the older brother of Frieza.
Dragon Ball Z: Cooler's Revenge
Cooler appears in the fifth Dragon Ball Z movie: Cooler's Revenge. The movie opens with Frieza destroying planet Vegeta. In his ship, Cooler notices a space pods coming from the planet, a space pod containing the baby Goku. Cooler tells his men to let it go, because he believed that it was Frieza's fault that someone escaped. Years later, Goku would become a Super Saiyan and defeat Frieza. When Cooler found out about this, he and a few of his best forces headed to Earth to restore his family's honor. Cooler confronts Goku, and tries to blast Gohan, but Goku gets in the way of the blast. Krillin takes Goku away while Gohan goes to get a Senzu Bean to heal Goku. After getting the bean, Cooler's forces catch up to him, but Piccolo comes in to save him. Gohan eventually gets to Goku and gives him a Senzu Bean. Goku confronts Cooler, now fully healed, and finds that Cooler had beaten Piccolo. Goku begins to fight in rage, and is able to keep up, but Cooler reveals that he has one more form than Frieza, and transforms. After transforming, Cooler fights Goku effortlessly, and has no problem fighting Goku in his Kaioken form either. Cooler begins destroying things all over, and in the process kills a bird. This makes Goku think about what will happen to the people he loves if Cooler wins, and he transforms into a Super Saiyan. After Goku transforms, Cooler finds that he cannot keep up with him, so summons up a ball of energy, to destroy the planet which would kill Goku. Goku uses a Kamehameha and pushes Cooler back, straight into the sun. As he dies, Cooler realizes that Goku was that baby in the space pod twenty years ago and he was a fool to have let the space pod go over twenty years prior.
Dragon Ball Z: The Return of Cooler
Goku is told to go to planet Namek by Dende, who senses that something is wrong there. Goku is confronted by a Metallic Cooler on Namek. Meta-Cooler reveals that he plans to use the Nameks as a bio-fuel for the metal planet, the Big Gete Star. After fighting him a little while, Goku discovers that Meta-Cooler will just regenerate after he is attacked. Goku, even after turning Super Saiyan, has trouble fending off Meta-Cooler. Then, as Meta-Cooler was choking Goku, Vegeta arrives, and begins to help Goku fight Meta-Cooler. Vegeta goes Super Saiyan and together they are able to defeat Meta-Cooler. Vegeta and Goku are quickly outmatched when thousands of Meta-Cooler attack, and brought to the core of the metallic planet, where the star leeches their energy. Goku wakes up, and concentrates a ball of energy. Meta-Cooler creates a giant body of metal, but Goku throws the energy at him, Meta-Cooler is hit by the blast, which causes the star to explode.