Step 15: Draw a couple of thin, triangle- like shapes on top of the head, on the sides, for the costume's ears. Some comic book pencilers draw Batman's ears long, while others draw them shorter. You can draw yours whatever length you want.
Step 16: Darken the outer edges of the initial guides to create the shape of Batman's head.
Step 17: Add a few more lines throughout the head for extra detail. Draw some lines on the head to emphasize the shape of Batman's mask and some on the chin to give him more character.
Step 18: Darken the lines under the head to create the neck and the trapezius muscles. Add two long, horizontal lines below the head for the collarbone. Draw a series of short, diagonal lines directly under Batman's chin for the neck muscles.
Step 19: Use the initial shapes on the left side of the body to draw Batman's arm. Simply follow the path of the guides and darken the outer edge of the shapes to create the arm. You can make the shape of the arm a little wider than the guides for bigger muscles. Add a few lines within the shape of the arm to emphasize the muscle structure.