Cooler is the main villain in the fifth and sixth movies of the anime Dragon Ball Z, introduced as the older brother of Freeza, and the oldest son of King Cold. His character was designed by Akira Toriyama, the original manga author, for Toei Doga's theatrical production. Like his brother, he can push his body through transformations to increase his power. Although only two forms are seen, it is stated in the fifth film that Coola possesses the same number of forms Freeza does, as well as a fifth and more powerful form.

He first travels to Earth in Cooler's Revenge to kill Goku, the saiyan that fought his brother. He ends up fighting Goku in his final form. Once transformed, he increases dramatically in size, speed, and strength; four horns grow to form a crown atop his head as spikes form on his forearms, and he now sports a facemask of sorts, hiding all facial features save his eyes, which are now red and pupiless. In the end, he is sent hurtling into the Sun by Super Saiyan Goku. Some of his remains merge with the Big Gete Star, allowing him to take control of it and create an indefinite amount of mechanical clones of himself that can constantly repair and improve upon themselves. Capable beyond his organic self, these Metal Coolas are a match for two Super Saiyans and now retain the ability of Shunkan Ido ("Instantaneous Movement"). Coola uses his newfound resources in a bid to absorb New Namek in Return of Cooler, but Goku and Vegeta destroy both him and the star in the end.

He later makes cameo appearances in Dragonball Z: Fusion Reborn and Dragon Ball GT, when all villains escape from Hell. A phantom Coola, along with what appears to be a resurrected Freeza, Tullece, and Lord Slug, attacked Goku and his friends in the Famicom game (and later Playdia re-make) Gaiden: Saiya-jin Zetsumetsu Keikaku (Side Story: The Plan to Eradicate the Saiyans) (an OVA was also released on VHS in August 1993), but these are merely false ghost-warriors meant to harass the heroes.

(Source: Wikipedia)