Unlikely Cloven Weapon
The Plasma Grenade is a weapon of Cloven origin, which is exatremely effective for taking down large groups of enemies. It contains a substance which sticks to a surface once it connects, which means that it can be stuck to an enemy, who might then run back to his allies, leading to far more casualties than could be obtained with a single frag.
Due to the nature of the weapon, it can only be obtained throgh collecting intelligence throughout the campaign. However, it can only be collected while playing in Infected mode, making it a much more exclusive weapon.
So far, the Plasma Grenade has only appeared in Resistance Retribution.