Step 11: Darken the football shape of Stewie's head. On either end of it draw a small curved line similar to a letter C for his ears. Draw a few lines within Stewie's ears to indicate the inner structure.
Step 12: Draw Stewie's hair as nine tiny curved lines above his head. Draw the one in the middle first above the vertical construction line. Then draw the ones above his ears, then just fill in the remaining six.
Step 13: Use the initial lines as guide to draw the right arm. Attach the arm to Stewie's head and angle it at the bottom to create his sleeves. Draw a few curved lines at the bottom of the U-shape to create his fingers.
Step 14: Again use the initial lines as guide to draw Stewie's body. Round out his torso a bit and the bottom cuffs of his pants too.
Step 15: The left arm is mainly behind Stewie's body, so only draw the visible portion of it. Angle the line to create the sleeve and draw a curved line for his thumb.