After a fierce but funny feud between the flightless birds and the scheming green pigs on their respective islands, both groups find themselves facing a new threat. A mysterious third island, ruled by the enigmatic Zeta, begins launching icy projectiles aimed at both Piggy Island and Bird Island, endangering their very existence. Despite their history of antagonism, the birds and pigs realize they must set aside their differences and come together to combat this shared formidable foe.

Red, the reluctant hero bird, along with his friends Chuck, Bomb, and Mighty Eagle, join forces with Leonard, the leader of the pigs, in an uneasy alliance. Together, they devise a plan to infiltrate the third island and stop Zeta. Along the way, they recruit Silver, a smart and inventive member of the avian community, and a quirky team of pigs. To succeed, they must overcome quirky gadgets, numerous mishaps, and the deep-seated mistrust between their species, all while learning important lessons about friendship, teamwork, and forgiveness.