Step 20: Darken the top part of the initial guides to create the back. Curve the line down across the initial circle so that it creates a skin fold and meets the hind leg at the bottom. Add a curved line inside to make the skin thicker. Darken the guide at the bottom for the underside of the rhino's body. Darken the left side of the initial circle to finish the shape of the body. Connect the line to the leg at the bottom but add an extra curved line in the middle for another skin fold.
Step 21: For a cleaner look, erase as much as you can of the initial guide lines. Don't worry about erasing all of the guides. It's okay to leave some behind. Re-draw any final sketch lines you may have accidentally erased.
Final Step: Add some shading to your rhinoceros drawing to give it more dimension and volume. Pick the direction of the light source when shading so that the shadows are consistent with it. Vary the pressure on your pencil to get different degrees of tonal value. Add an extra-dark value close to the skin folds to really emphasize the overlap. Don't worry about shading too smoothly. The rough value will give the rhino's skin a bumpy texture. For a more detailed guide on how to shade, check out this tutorial: How to shade.
You can add even more value throughout the rhino's body for extra detail. Indian rhinoceroses are basically gray, so simply add a medium value to the entire body. As you add the value, leave a thin area along the skin folds blank to act as a highlight. If you make the value for the body darker than the shadows, make the shadows darker too. Shading can be time-consuming, so be patient and take breaks. It's always a good idea to use reference for a more accurate drawing.
Add a cast shadow underneath. This helps to ground the rhino ceros so it doesn't appear to be floating. Don't forget to pause the video after each step to draw at your own pace.