- "Make red your claws with human blood... obliterate the human filth... torch the humans like a wood... the rebellion is coming..."
- ―The Red Rage
The Dragon Rebellion or Red Rage was an insurrection led by Furious against humanity.
Many centuries before the events of How to Train Your Dragon, the dragon Merciless led an army of dragons in a war with humanity. Using the Dragon Jewel, Hiccup Horrendous Haddock I banished Merciless from the Barbaric Archipelago. Dragons and humans then lived together in harmony. Humans treated dragons as equals. The two species sat around fires as equal partners. At hunts dragons were fed first, and their opinions were taken into consideration before the hunts. Hiccup the First even talked to dragons casually, just like if they were humans.
Despite the equality between humans and dragons during Hiccup the First's lifetime, the equality began to fade during each generation of Kings of the Wilderwest. Each king treated dragons worse than the last and used the power of the Dragon Jewel, the power the Wodensfang gave to Hiccup the First to do evil to dragons. This culminated in Grimbeard the Ghastly, who refused the Dragonmark and enslaved dragons as well as humans to build the city on the Island of Tomorrow.
Grimbeard's third son Hiccup Horrendous Haddock II saw this tragedy, and attempted to hold a peaceful petition with thousands of dragons, demanding that the dragons be freed. This petition was going to be led by Furious, a young Seadragonus Giganticus Maximus, as well as Hiccup the Second's dragon-brother, who grew up with Hiccup the Second till he was seven years old inside a cave tended by Grimlers. Before the protest started, Thugheart, Grimbeard's jealous son told Grimbeard that Hiccup the Second was going to attempt to take the throne with an army of dragons. When the dragons arrived on the day of the petition, Grimbeard drove the Stormblade threw Hiccup the Second's chest, killing him. In his dying words, Hiccup the Second said that he meant him no harm, saying that a dying man doesn't lie. Grimbeard looked into his sons eyes and knew it was the truth. Furious attempted to kill Grimbeard in revenge, but Hiccup the Second intervened, telling Furious that he didn't want his father's blood on his hands. Moments after Hiccup the Second died, Furious snatched his corpse from Grimbeard's arms and buried it on the Bay of the Broken Heart, the place that Hiccup the Second's human mother, Chinhilda supposedly haunts. Afterwards Furious was subdued by humans and imprisoned on Berserk.
Furious became known as the Beast, and the Berserker Tribe regularly held human sacrifices to him. During his time on Berserk, Furious had grown an extreme hatred towards humans. He believed humans were treating dragons like slaves, and that the only way he could ever be truly be free is that if every human being was dead.
In How to Break a Dragon's Heart, a century after Furious's imprisonment, Hiccup Horrendous Haddock III was being fed to the Beast. Before the Beast could swallow Hiccup, the little viking shouted "Stop!", and spoke in Dragonese. The Beast pulled Hiccup out of his mouth and Hiccup told the Beast that he knew knew he was actually Furious. Hiccup figured this out right before he was put into Furious's mouth by looking at the enormous dragon's chest and seeing a scar. Furious received this scar from leaping in front of Hiccup the Second right before Grimbeard thrust the Stormblade. Furious was angered by the fact that a human knew his name and was speaking dragonese. Furious told Hiccup about how being imprisoned on Berserk drained his compassion for humanity. Furious even said that if he could relive the past, he would abandon Hiccup the Second's corpse on the Bay of the Broken Heart and "leave him for the fishes to eat". Hiccup tried to reason with Furious, but to no avail. Furious stated that he looked into the past and the future and believed that humans and dragons cannot live together, and that one must die for the other to live. Furious then stated that he would give the humans one year's time before he returned to the Barbaric Archipelago with a new dragon rebellion (he considers the peaceful protest to be a rebellion) that would extinguish humanity.
- In book nine, One Eye stated that he will join the rebellion. However, in book 12, Furious said that he refused to fight alongside the Dragon Rebellion.