In the peaceful town of Timberline, a 900-pound (408 kg) grizzly bear named Boog enjoys a captive, but pampered existence and spends his day as the star attraction of the town's nature show while at night living in the Garage (house) of park ranger Beth, who has raised him since he was a cub. One day, the sadistic hunting fanatic Shaw drives into town with a one-antlered deer strapped to the hood of his truck. After Boog frees him, the deer follows Boog home to find him sleeping in the garage. To wake Boog up, the deer throws rabbits at the window and introduces himself as Elliot. He tells him to be "free" from his garage captivity and introduces Boog to a world of sweet temptations he has never known.
After falling head over hooves in love with Giselle, Elliot's road to the altar takes a slight detour when Mr. Weenie is kidnapped by a group of pampered pets determined to return him to his owners.
One spring morning, Boog awakens after hibernation and plans an annual guys trip to spend time with his male best friends. Unfortunately, Elliot has distanced himself from Boog since he had started a family with Giselle. They are now the parents of three children: Gisela, Giselita, and Elvis (with Boog now being the adoptive uncle). Boog is disappointed since everyone else wants to spend time with their families, which makes him go on the guys trip by himself with Dinkleman however, this soon leads him to a Russian traveling circus called the Maslova Family Circus.