Step 20: Use the long line on the right as a guide to draw the armadillo's tail. Follow the path of the guide but make the tail thicker at the base and pointier at the end.
Step 21: Add a series of short, curved lines within the shape of the armadillo's tail to indicate its various segments.
Step 22 (optional): 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 that you may have accidentally erased.
Final Step (optional): Add some shading to your armadillo 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. Continue adding the value until the entire body has the appropriate shadows.
Add a cast shadow underneath. This helps ground the armadillo so it doesn't appear to be floating. Use a darker value near the middle and a lighter value along the edge for the shadow's diffusion.
You can add even more value throughout your drawing for extra detail. Draw squiggly lines all over the body to give the overall impression of the scales instead of drawing every individual scale. Don't overthink the squiggles. Just add them randomly all over the body for a scale-like texture. You can add the texture lightly at first, then when you're comfortable, gradually build up to the level of darkness that you want. Use a lighter value for the scales near the middle of the body for a shinier effect.
It's always a good idea to use reference for a more accurate drawing. Shading can be time-consuming, so be patient and take breaks. Remember to pause the "How to Draw an Armadillo" video after each step to draw at your own pace.