This usually docile grass grows in many parts of the world. It doesn't normally pose a threat, but when disturbed by grazing animals (or landing of a ship, for that matter) it tries to snare any mobile lifeforms with its strong, flexible strands. It doesn't pose a real threat to anyone, unless you doze off for many hours in it and let yourself be digested. In battle conditions, the Evil Grass slows down movement. I suggest using explosives - take that, Grass!