A star-studded cast provides the voices for the prehistoric creatures in this computer-animated feature set 20,000 years ago as the Ice Age approaches. Seemingly anti-social Manny, a woolly mammoth (voiced by Ray Romano), acts as if he just wants to be left alone. When he meets Sid (voiced by John Leguizamo), a sloth, the two become unlikely travelling companions. The plot thickens when the duo finds a human infant and decides to try to return the child to its 'herd'. Manny slowly but surely reveals his heart of gold, while Sid continues to provide comic relief. Diego (voiced by Denis Leary), a saber-tooth tiger with ulterior motives, soon joins them in their search for the humans. Ultimately, this group of misfits becomes its own herd, learning about friendship and loyalty as they brave snow, ice, freezing temperatures, predators, hail, and even boiling lava pits. All the while, a saber-tooth squirrel, Scat, provides comic relief as he valiantly struggles with an acorn.
Boog, a domesticated 900lb. Grizzly bear finds himself stranded in the woods 3 days before Open Season. Forced to rely on Elliot, a fast-talking mule deer, the two form an unlikely friendship and must quickly rally other forest animals if they are to create a rag-tag army against the hunters.
Rodney Copperbottom is a small town robot who has a gift for inventing things and dreams of something greater. Armed with his talent he embarks on a journey to Robot City to meet his idol, the majestic inventor Bigweld. As he tries to navigate his way around this new city, Rodney befriends the Rusties, a ragtag group of street-smart bots and together they encounter unsavoury characters who try to derail Rodney's plans to find Bigweld and save Robot City.