On an isolated island, there live many kinds of happy and carefree birds. However, there are always outliers among them, such as the solitary Fat Red (voiced by Jason Sudeikis). His orphan and strange appearance make him the object of ridicule and mockery by other birds. Over time, Fat Red also developed a narrow-minded and irritable character. While being sentenced by the judge to attend an emotional management course, he met the extremely fast dart Yellow (voiced by Josh Gad) and the bomb Black (voiced by Danny McBride) who would cause an explosion if he was not careful. The three freaks made a lot of jokes. Not long after, the mysterious green pig Leonard (voiced by Bill Hader) came to the island with his men. They showed friendly faces, but seemed to be planning something in secret. Only Fat Red on the island was wary of the arrival of the green pig, and his worries were soon verified...