When Sid accidentally destroys Manny's heirloom Christmas rock and ends up on Santa's naughty list, he leads a hilarious quest to the North Pole to make things right and ends up making things much worse. Now it's up to Manny and his prehistoric posse to band together and save Christmas for the entire world.

Back when the Earth was being overrun by glaciers, and animals were scurrying to save themselves from the upcoming Ice Age, a stupid sloth named Sid, a woolly mammoth named Manny, and a saber-toothed tiger named Diego are forced to become unlikely heroes. The three reluctantly come together when they have to return a human child to its father while braving the deadly elements of the impending Ice Age.

Manny the woolly mammoth, Sid the sloth, Diego the saber-toothed tiger, and the hapless prehistoric squirrel/rat known as Scrat are still together and enjoying the perks of their now melting world. Manny may be ready to start a family, but nobody has seen another mammoth for a long time; Manny thinks he may be the last one. That is, until he miraculously finds Ellie, the only female mammoth left in the world. Their only problems: They can't stand each other--and Ellie somehow thinks she's a possum! Ellie comes with some excess baggage in the form of her two possum "brothers"-- Crash and Eddie, a couple of daredevil pranksters and cocky, loud-mouthed troublemakers. Manny, Sid and Diego quickly learn that the warming climate has one major drawback: A huge glacial dam holding off oceans of water is about to break, threatening the entire valley. The only chance of survival lies at the other end of the valley...

Back when the Earth was being overrun by glaciers, and animals were scurrying to save themselves from the upcoming Ice Age, a stupid sloth named Sid, a woolly mammoth named Manny, and a saber-toothed tiger named Diego are forced to become unlikely heroes. The three reluctantly come together when they have to return a human child to its father while braving the deadly elements of the impending Ice Age.

In a robot world, a young idealistic inventor travels to the big city to join his inspiration's company, only to find himself opposing its sinister new management.