Coca-Cola Bear is Pepsiman's arch-nemesis who rules the Coke Federation, which occupies Baffin Island and a couple of nearby islands (formerly the eastern half of Antarctica) after his loss to Pepsiman in the Soda Civil War, which took place on Antarctica.
He is not as strong as Pepsiman. Thus, feeling threatened by Pepsiman, he redeemed himself (we wouldn't still call him a hero, though) and ran away scot-free, then moved his country all the way to Nunavut where he'd get help from Peter Pan in exchange for helping him with his bootleg empire, before ultimately being murdered by Chip and Dale.
Eventually, he also took part in the Sewer Penguin War on the side of the penguins.
Coca-Cola Bear is also a dude unlike Pepsiman, according to Thanos.