Guide lines - Let's work on drawing a ferocious pitbull dog. First, we need to lay down our basic construction guides. Using a 2H (or harder) pencil, we are going to lightly sketch in two circles. The first circle will represent the shape of the body, so it will need to be slightly warped on the bottom right side, as if being pressed in. The second circle will represent the head and should rest near the top, left side of the larger circle. Pitbulls have fairly large heads in relation to their bodies, and because of our perspective, make the head circle almost two-thirds the size of the body. Draw an X near the top, left section of the head circle as a guide for the center of the face. Remember to draw lightly, as these lines will be erased after we ink the image.
Head - Now that we have our guide lines down, we can begin working on the head. Although pitbulls are friendly by nature, our pitbull is mean and ferocious! To make his expression exemplify rage, he needs to be snarling and bearing his teeth. Be sure to draw the upper and lower canines larger than the rest of the teeth. Also be sure to show some of the dog's gum line between the teeth and lips - doing this will make the animal look even meaner. These animals have a lot of loose skin around their mouths, so draw plenty of wrinkles and folds around the mouth and on top of the snout. You can give the dog more personality by making one of his ears fold down while the other points back.
Collar - To make the dog even more vicious looking, we can give it a spiked collar around it's neck. Be sure to draw the edge of the collar as a way to give it dimension, otherwise it will look like a flimsy strip of paper wrapped around the dog's neck. Remember to add the buckle - it may seem like a minor detail, but by adding the buckle, it helps the image become more believable. You can give it a bit more character by adding a small piece of the collar strap hanging out from the buckle. Make sure the spikes are evenly placed around the collar.
Let's start making our way down the body by drawing in the front legs and chest. These dogs are very muscular and have smooth fur, so be sure to draw in some muscle ripples, especially on the shoulders. Plant the paws far apart so that the dog looks like he has a solid stance. Don't forget to draw the claws!
We can now draw in the hind legs. Again, make the legs look muscular and plant the paws far apart. Pitbulls do not always have long tails, so in this case we can assume that our dog has a short tail which we cannot see at the angle.
Now that we have our figure drawn in, this would be a good opportunity to take out a brush pen or marker, such as a Micron, and carefully trace over figure. Be sure not to accidentally trace over our guidelines from step 1. After you've inked over the image, use a kneaded eraser to erase all of the pencils lines. You will now have perfectly clean, black lined figure drawing of a pitbull. But we are not finished yet!
Shadow - Establish your light source so we can begin filling in the shadows. In this case, our light source is coming from the top left of the page, a little bit in front of the dog. Add shadow on the backside of the large muscles and on the underside of the dog's chest. Remember that light bounces off the ground, creating a thin strip of white along the bottom egde of the chest. Don't forget to shade inside the ears, mouth, and underneath the large lips. Add shadow behind each spike of the collar. To help create the illusion of a reflective surface on the spikes, insert a thin strip of shadow on each spike and on the buckle. You can use this method to create the same effect on the teeth. To make the dog look even more violent, fill in this iris of the eye with black so that you can't tell where the iris ends and the pupil begins.
Rendering - As a way to give the image a greater sense of depth and shadow, we can blend from light to dark by adding crosshatching with the use of a Micron marker, and feathering with the use of a brush or brush pen. Heavily crosshatch darker areas such as inside the mouth and ears, and provide feathering along the contours of the muscles. Be sure to thin out crosshatch lines as you get closer to the light source, and when feathering, taper your brush strokes to a fine point as they get closer to the light source. This is also a good opportunity to add some texture, such as roughing up the collar, teeth, and claws with random texture lines.
To finish off the illustration, let's insert a few highlights using some opaque white paint or white ink. Put a white dot in the exact same location of each eye facing the direction of our light source. The shine on the eyes will bring the image to life. Add white lines at the base of the feet so that the feet do not merge into the shadow too much. As a final touch, give the dog some drool and spit flying out of his mouth. And that's it! You have now illustrated a pitbull! Nice work!