The Homo Inhumanum, although generally homogenous in terms of DNA, have a very broad spectrum of physiological traits. The size of a Brute speciment is the most common trait that shows extreme variation. However, when a Brute exceeds a specific size it begins to show very different and distinct behavior.
Brutes that exceed the 2.50 m height mark (8' 2") show a distinct increase in aggression that causes other Brutes to ostracise them from their groups. Commonly refered to as Berserkers, these Brutes are a menace on the battlefield. They carry huge weapons, commonly found on vehicle mounts, and cover themselves in metal plates which makes them almost invulnerable to small arms fire. Aside from its impressive ordnance, the Berserker mostly owes its name to its tendency to go berserk when it scores a kill. The creature gets so excited when it manages to deal damage to the enemy that it enters a second wind and allows it to press the attack.
In the game
The Brute Berserker is the heavy weapon platform available to the Homo Inhumanum. They can be armed either with a 50 cal machine gun or an AT Missile Launcher allowing it to act both as an anti tank and an anti infantry unit. Aside of their ranged armament, the Brute is also armed with a melee weapon (in reality their ranged weapon used as a club) which allows it to deal substantial damage in melee as well. In terms of movement, the Berserker may make a normal move every time a friendly unit moves within 12". Coupled with the faction special rule and the Brute Warlord trait this means that the Brute Berserker can move several times during an activation.