Step 2: Drawing The Head
When you have that part done. Try doing a curved line for the top part of its dome like head. Use the middle line inside the circle and arc back. Take the horizontal line and make a jaw with a chin. With that same horizontal line make the dome top were the shiny or detailed part will be cut off. When you get done with that, erase all of the lines in the center of the circle to make it clean. Add the mouth and the lines that separate the mouth in segments. Add some teeth to it. NOTICE that they have some human like teeth in the front. The rest are sharp.
Sorry that the third photo is blurry.
Step 3: Drawing The Arms And Body
For the body. See how it has a bigger base or wider stomach. It's a warrior so it's a bit bigger than a lurker, yet smaller than a spitter. The block lolling things going down its chest are the rib connecting parts.