In Norse mythology, the berserkers were known for their ferocity

Explanation

They were elite warriors serving Odin, often described as "mad as dogs or wolves", howling and biting their shields while fighting with the ferocity of their totem animals. They were renowned for entering a trance-like fury known as berserkergangr before battle, a state believed to grant them superhuman strength, immunity to pain, and protection from fire and iron. Fun fact: the term "berserker" likely derives from ber-serkr, meaning either "bear-shirt" (referring to wearing bear pelts) or "bare-shirt" (fighting without armor).