The Duplo Aliens (voiced by Sawyer Jones, Liam Knight, Cora Miller, Graham Miller, Emmett Mitchell, and Ollie Mitchell) are a race of giant aliens made of Duplo blocks that come from the planet Duplo. As a result of "The Man Upstairs" allowing his younger daughter Bianca to play with him and Finn, the Duplo Aliens arrive with the lead Duplo Alien announcing their plans to destroy everyone before the film ends in a cliffhanger.
