In FusionFall, Humungousaur can be found at Dinosaur Pass in The Darklands, located near the Infected Zone. Like Alien X, AmpFibian and Echo Echo, he was transported here by Dexter's invention that sends Ben's alien forms across the universe. His brute strength has proven useful in The Darklands, where the forces against Fuse are not nearly as strong as those in other areas of the world. His missions consist of studying the dinosaur-like fusion monsters in the area, which remind him of his home planet, Terradino. He comically expresses a feeling of being overworked and references Ben's overuse of Humoungousaur as a transformation throughout the Ben 10 franchise.