The adjective ferocious means more than merely angry or active. If you can imagine the wildest, most savage animal ready to rip your arms off and shred the muscles, you would be imagining a ferocious beast.
Although we most often think of the word ferocious as referring to wild animals, it can also be used to describe anything characterized by an extremely high level of energy or even violence. Think of it as the extreme opposite of peaceful. For example, sports fans at a soccer match often present a ferocious appreciation of the game, sometimes to the point of destroying the stands or storming the field to fight with the players!