Step 20: Draw a series of spikes along the top of the neck, behind the head. The spikes should be triangular. Follow the path of the neck as you draw them. Make the spikes smaller the farther back along the neck they are. You can make the spikes smaller, bigger or skip them altogether for a simpler drawing. When you finish drawing the spikes, darken the rest of the neck shape.
Step 21: Use the angled line on the top, left side of the body as a guide to draw the first part of the wyvern's dragon-like wing. Follow the path of the guide and draw the wing around it. The shape should be similar to an arm. Sketch lightly at first to get the shape right. Make the tip at the top pointy. When you get the shape right, darken the lines. The shape should be skinny with a few curved lines for the muscle structure. Add a spike at the joint. Make the base at the bottom that attaches to the body wide.
Step 22: Use the lines on the left as guides to draw the rest of the wing. First darken the initial lines to create the outer structure of the wings. At the bottom , draw a series of V-shapes lines for the folded edge of the wing. These V-shaped lines are basically the wvyern's stretched fingers. The lines should overlap a little to emphasize the skin between the fingers.
Step 23: Draw a curved line on the left side of the body to indicate where the bottom of the wyvern's wing is attached. At the bottom, draw another V-shaped line between the first two.
Step 24: Use the shapes under the neck as guides to create the wyvern's body. Darken the outer edges of the initial guides but make the bottom part a bit thinner.