At the bottom of the body, use the pen tool to draw the shape of the wings. Once satisfied with the shape, create a new layer. DO NOT delete the work path yet!

Click on the new layer to activate it. Then click on the select path icon from the paths palette. Then from the select menu, choose Modify / Contract and put in 5 pixels. Fill the now contracted selection with white paint.

Return to the previous layer. Reset the paint color to black. Go to the paths palette and click on the fill paths tool to fill the original path with black. Merge the two layers. You should see a black outline of your wings. Use the magic wand to select the white insides of this outline and then delete that selection, leaving only the black outline.