I know our races are meant to have organs and limbs, But I'd like a race of blobs. They sense their surroundings using a type of echolocation, they vibrate which sends out waves along the ground, which then come back and form a good image of their surroundings with colour. They can also get a slightly less detailed image without colour using actual echolocation.
They feel pain, but in a different way to humans. A prick in the foot would feel like very little to them, while a slash with a sword would hurt a great deal more than humans.
So, small amounts of pain fell like less pain than humans, while the more pain there is, the more pain they feel. There is a point where they feel the exact same amount of pain as humans. A strong sword slash would send them running, while a jab with a dagger and they'll digest you.
They're height and size varies, as they age, they grow. They range from about 8' to almost 16' and live spread out in fields. They generally eat grass, leaves and sometimes animals if they can be bothered, and live in herds of about 100. They are green with a tough outer skin, about the strength of leather Their skin is about 3 inches thick, and dry. When cut, the inside of the wound is wet and regenerates almost instantly. It is covered in hair. The inside is a thick goop, which is the life source of the creature. They divide to reproduce, when they reach 16 feet they divide. Some do not divide at that point, and the chance of this happening is close to 10,000 to 1. Those mutants come to around 48 feet high before they divide (into quarters, and those blobs have the 10,000-1 chance of mutation). Then, about 10,000,000-1 is a blob that keeps growing until about 150-200 feet high, and doesn't divide. This is not fact, as there are 10 million blobs in the continent. The blobs grow at a rate of 1 foot per year and when they divide, one of them will die at 14 feet, the other going on to a normal life.
How to combat:
For overkill, catapaults will squish them, killing them instantly. Be careful though, if they see, they will compress and the rock will bounce off harmlessly, for them at least. Just hope it doesn't rebound and hit you.
With foot soldiers, they should cut out a large square of skin. This would take almost ten men just to kill one, though, since their wounds regenerate almost instantly.
The best way to kill them is to arm your soldiers with hooked daggers and stab repeatedly, as they are so sensitive to pain on this level, only a few stabs will kill these monsters. Be careful, if you stab, the monster could pull you in through the wound and digest you.
These monsters are amazingly passive, and will not eat humans even if they are starving. They will only fight if attacked. Then, they'll just eat you.
They might sound overpowered, but their major weakness is pain. Hand weapons are also a weakness because you can rip them apart with your bare hands. Or cutting them in half. Then they die.