you make a mistake. if you're struggling drawing the circle, trace the outer rim of a coin, a lid or any other object with a circular edge.
step 2: draw another circle on the right the same way. this will be a guide for the back of the pachycephalosaurus's body. this circle should be slightly bigger than the first one, and their edges should touch. don't draw the circles higher or lower. draw them at the same level.
step 3: draw yet another circle on the left side as a guide for the pachycephalosaurus's head. this circle should be smaller than the others. there should also be a small space between it 