Fredzilla is an alternate form for Big Hero 6 team member, Fred. He first appears in Episode 29 of Big Hero 6: The Animated Series. He was created by accident when Fred accidentally steped on a broken test tube of Kaiju DNA while the team was hunting down a villain who was doing genetic experiments on humans. This event mutated Fred's blood and transformed into a gigantic 300 foot reptilian monster. In this state, Fred then proceeded to go on a rampage through San Fransokyo, destroying all in his path, until he was finally returned to normal by the rest of the team.
He would later reappear in the Season 2 finale, Revenge of Fredzilla, serving as an anti-hero who is working to kill a bigger threat to mankind: The GIMOs, 2 giant insect-like monsters that were converging on San Fransokyo to mate. He fought the creatures in the middle of the city before finally killing them both. He was then cured and returned to normal once again by his friends.
A 300-foot force of sheer destruction, Fredzilla is NOTHING like the beloved fanboyish, good-natured Fred the rest of the team has known to love. After a lab accident while hunting a villain, that loveable oaf has transformed into a thoughtless savage. When the monster makes landfall in San Fransokyo, NO ONE is safe. Cars get crushed, buildings smashed, cities on fire, it's a force like no one has ever seen.
Fredzilla's appearance looks exactly the same as his appearance in the original Big Hero 6 comic book. He is a giant 300 foot-tall Godzilla-like creature, with red scaly skin. He is highly muscular, with huge muscular arms and bulky legs that can crush anything in the monster's path. It also has has razor sharp teeh and claws, as well as 3 large fins on his back. 2 smaller ones that run from his shoulders to the start of its tail and one large one that runs from the end of its neck to the beginning of its tail. It not only uses its claws, teeth and sheer size for causing destruction. It also possesses an enormous laser-like blast of heat that it can shoot from its mouth that can decimate entire city blocks.
- Fredzilla's heat breath is a reference to the atomic breath weapon of the famous movie monster Godzilla.
- Fredzilla is the first character from the original comic books to make an appearace in the Disney series.