It begins at Jellystone Park where Yogi and Boo Boo have heard that Cindy Bear has gone missing, so the two bears sneak out of Jellystone to save her. After taking various vehicles to reach their destination, they discover that she’s being held captive by some greedy circus owners and the hunter to kidnapped her known as Victor Quartermaine. A friendly weasel, I Am Weasel, and his idiotic baboon friend, IR Baboon, come to their aid and save her, as well as giving her kidnapper the slip with his dog Phillip watching as he knows they’ll get even with that bear.
Meanwhile, two boys, Wirt and Greg, accompanied by their frog and bird, Beatrice are wandering through the woods where they are attacked by Goblins (from The Princess and The Goblin) and Doldrums (from The Phantom Tollbooth). However, they are soon saved when singing from a distance scares the monsters off. And the singing in question is coming from Yogi, Boo Boo, Cindy, Weasel and Baboon. They decide to follow the talking animals and see if they can help them find a way back to where they belong.
After some venturing through this new world, they run into Puppycorn and Hawkodile (from Unikitty) who will provide assistance in holding off whatever villains are in their way. They later wind up in the Big City (from Sheep In The Big City) where they encounter Shaun The Sheep and his flock who have all got caught during this war that is going on and they decide to join Yogi and Wirt’s team too. After some hiding out from General Specific and Private Public, they hide in the Big City’s casino for animals where they run afoul of Warren T Rat and various bad cats.
They all escape and decide to take a river route which could help take them home. During so, Yogi croons for Cindy, but the romantic moment is interrupted when two escape pods crash land into a forest area which Wirt, Yogi and friends are currently in, the escape pods contained two clueless teenagers, one with whose head is stuck in a Retro-looking TV and the other a spunky looking woman with grey hair and an odd Panda-like mark on one of her eyes, Retro and Pandy from Dead Leaves, and a shapeshifting All Purpose Animal and his friends who is a mute magician that looks like Charlie Chaplin, Ralph and Mumford from Twice Upon A Time. Yogi decides to let them join their group so the bears and kids can have the help they need to find their ways back to their homes.
Boo Boo, during this journey, takes great interest in Retro and Pandy. He asks them why they and the two Twice Upon A Time characters wound up in all this insanity and Pandy replies by telling him that before this entire war began, she and Retro, as well as Ralph and Mumford, were enslaved by Lord Boxman and his Robot goons where they were forced to make merchandise for him up until Botch and his alliance took over and forced Boxman and his Robot Children into providing the scream fuel needed for his Nightmare Bombs. Boxman’s partner Professor Venomous had the prisoners freed via escape pods which wound up where Yogi’s crew were and the four new characters join the group in order to prove themselves as heroes.
This wild quest of theirs takes them across multiples areas during the series, with a notable one being the kingdom of Cagliostro (from The Castle of Cagliostro), and they wind up doing battle against various foes. Will our odd set of friends ever find their way home?