How frequent was it to see "bezerker" styled troops in barbarian tribes when fighting? Were they really that big like in movies or was there a lot of intimidation factor (armour, weapon choice, decor, etc) ?
I talked about literal Viking berserks in a month-old thread here. In short, the stereotypical image we have of berserks is an invention by story-writers of 13th century Iceland, but there are elements that might be rooted in reality.