科米蛙将面对最大的挑战:布偶团正在进行欧洲巡演,到达了柏林、马德里、伦敦等令人兴奋的城市。但很快一个和科米蛙长得几乎一模一样,却操着一口带有浓重俄国口音英语的青蛙大盗康斯坦丁,摇身一变,和他的搭档多米尼克(瑞奇·热维斯饰演)混入了布偶团,而可怜的科米蛙则被蒂娜·菲饰演的狱警娜佳打入大牢,身陷囹圄。此外,《摩登家庭》男星泰·布利尔将饰演国际刑警,调查这桩奇怪的案件。Flush with their revival's success, Kermit the Frog and his friends are approached by Dominic Badguy to go on a world tour. Unknown to them, this is all part of the sinister plan of Constantine, the world's most evil frog, to become the greatest thief of all time. After making sure that Kermit is jailed as himself, Constantine impersonates him to use the Muppets' tour as cover for his scheme. While Sam the Eagle and Inspector Jean Pierre Napoleon investigate, the Muppets find their boss seems strangely changed even as Kermit desperately attempts to escape to stop the impostor. Only when Walter, Fozzie and Animal realize the truth is there a chance to prevent Constantine from pulling off the crime of the century.