Fred is the last member of the current Big Hero 6 to be shown. The team meets up with him in the U.S. where he is already protecting the teams objective. Go-Go and Honey Lemon decide to test him which leads to a short rumble between Fred and most of the team ( Hiro did not participate). Fred took the team to football practice for a team Fred was helping coach where he stands up to Wasabi saying his loyalty was with his team (regarding football that is).
Fred seems to surround himself in a type of mysterious aura, shaped like a giant purplish-red kaiju, which acts like a massive suit of psionic armor when expanded to it's full-size. Even when used at less than half it's full height and stature, the aura seems to enhance some of his abilities such as strength and stamina but to what level and what else it is capable of is unknown. During Big Hero 6's battle with Everwraith at the behest of Spider-Man (who had been coordinating with the Japanese government) to try and stop Dr. Octopus' scheme, Fred demonstrated his aura's ability to protect him from injuries that would have normally killed a normal human, as seen when he leapt out of a jet several miles over Tokyo to deliver a powerful blow to the team's ghostly adversary.
Fredzilla appears in the feature-length animated Walt Disney film based on Big Hero 6. In the movie, Fredzilla is a young American boy with much of the same powers as he has in the comics.