Step 16: Inside the shape of the square, draw Grunkle Stan's torso. The opening of the suit should be similar to the letter V. Then draw the sides using the square as a guide and the bottom ,which is like an upside-down letter V.
Step 17: Add the detail of Grunkle Stan's suit inside the shape of the torso. Draw the thin bow under the chin using a series of short lines. Draw the suit's lapels as a couple of angled lines on the sides of the big V shape. Draw a small circle close to the bottom for the single button and a small crease on the bottom left side of his jacket.
Step 18: Use the angled line on the right as a guide to draw Grunkle Stan's other arm. Follow the basic shape of the guide as you make the arm thicker. Draw the shoulder pad and sleeves as curved lines. Draw a tiny circle near the sleeves for the button.
Step 19: Draw Grunkle Stan's hands by using the initial circles as guides. Within the shape of the circle on the left, draw a few curved lines to represent the fingers forming a fist. Add the hand at the top by drawing a few curved lines for the fingers. Some characters in Gravity Falls, like Grunkle Stan, Soos and most other adults, have four fingers and a thumb. Others, like Dipper, Mabel and Wendy, have three fingers and a thumb.
Step 20: Use the line and oval under the body on the left side as a guide to draw Grunkle Stan's leg and foot. Follow the basic path of the line as you make the shape of the leg thicker. Make the shoe pointier at the front and draw a heel on the back. Draw a couple of curved lines within the shape for the shoe's design.