Animation. Dennis lives in Beanotown with Mum, Dad, little sister Bea and his pet dog Gnasher. Gnasher is more than a dog to Dennis; he is a kindred spirit. Whatever Dennis does, Gnasher does with him.
Together with their friends Curly and Pie Face, Dennis and Gnasher believe the world truly is their oyster and that kids should make the rules. Not everyone agrees, including Mum and Dad. But Dennis and Gnasher are not going to let that stand in the way of their pursuit of fun!
Beanotown Park reopens after a year of being closed, but Dennis, his friends and many of the other Beanotown residents discover that all the fun has been taken out of the park. Dennis and his friends set about trying to make their own fun, and in the process, reclaim their park.
Using the remnants of the old park playground, Dennis and his friends create a giant monster to scare everyone away, but instead it does the opposite. An unlikely alliance with the colonel brings them together in the name of rescuing their park and claiming it back as their own.