Goliath

Goliaths are enormous and massive creatures that serve as the heavy artillery of the alien forces. Armed with two large guns on each side, they shoot energy bullets from them which burns the target. They can either shoot many small bullets for a long time or charge the weapons and shoot one big blast that does an area of effect damage.
They are some kind of robotic-organic hubrids, as the weapons attached to them are connected to their bodies, although they are probably stuck to them after they are born. However, the weapons are programmed to explode when their heart stops beating.
Goliaths were created as an attempt to stop relying on lower beings as servants. The sovereigns' ultimate goal is to have armies completely made of metal in the future, so that they will not rely on living organisms, where there is a chance of being betrayed. Also, the robots will be tougher and will last longer. This goal is still undergoing, since creating pure robots requires a lot of metal, something the aliens missed since thy did not have a planet. The hybrid Goliaths was as close as they could get
When it comes to their anatomy, it is pretty simple. All of their organs are into their chest, along with their eyes and nose. Their eyes are the only place on their body not covered in scales, so it is a weak spot on them and they die when shot in the eye. However, their eyes look very much like scales, which initially led the scientists to suspect they communicate with the world in other ways. They found out when a farmer informed them about how he killed one of them. The rest of their weak spots is covered in scales, making it difficult to break into. Where there are no scales, there is no organ behind it, so the injury in that spot is minor and non-lethal.
Their body is muscular and strong, almost inpenetrable by gunshots. They are highly resistant to pain, and although they are semi-mindless, they can aim pretty well.They have no skin, instead their flesh is exposed, except the parts that are covered with thick scales. Therefore, they are hard to kill, however there have been fond ways to kill them effectively. Such ways are:
*Shoot them with a powerful weapon, like a rocker launcher or a minigun.
*Shock them with high voltage electricity. Their body is a good conductor of electricity, so high voltage wil kill them easily.
*Shoot them in their weak spots. After they took a corpse of a Goliath, the scientists studied them and found some weak spots. Surprisingly though, a farmer they encountered along the way also managed to kill a Goliath by shooting it with his rifle in a specific spot.
*Jack Rogers also found a way to extract the weapons of the Goliaths after their death, and managed to turn them against them. Though this proved useful, the whole procedure is very hard and is rarely done.