First, bit"map" it out. This is the strategy I used to draw Tracker. Repeat following until completely drawn. Next, completely use red lines to trace out a body part with the bitmap as a guide. After that, trace it over with either pencil, or use circle to reshape to desired shape. Smooth, then reshape again. Finally, move on to the next body part.
Didn't expect anything about this. It was really hard, but I was able to use my complexity strategy on Diepic, Diepic!