Select the circle drawing function in the design program of your choice. Click and drag to create two circles, one on top of the other.
Select the pen tool and divide the top circle horizontally through the center. Extend the bottom of the top circle and both ends of the bottom circle to create rounded corners.
Use the same tool to draw elongated triangles on either side of the top circle. Select the line tool then draw two zigzagging lines coming out of the right side on the body. Bring them together at the top for the tail.
Use the pen tool to draw in the box-shaped arms, then switch back to the circle tool. Center two circles on the horizontal line in the top circle for Pikachu's eyes. Add two circles below but slightly further apart for the red cheeks.
Select the pen tool to draw in the mouth and small reflections on each eye. Use the eraser tool to delete guide lines or missteps.
Select the circle tool, then click and drag to draw a vertically oriented ellipse. Click and drag to place a horizontally oriented ellipse on top of the first.
Use the pen tool to make a horizontal line across the center of the top ellipse. Use the circle tool to draw a small ellipse to the left side of the first ellipse for Squirtle's tail.
Use the pen tool to capture the arch-shaped sockets where the arms meet the body. Extend the arms and feet with the pen tool, then draw in the swirl of the coiled tail.
Outline the edge of the shell around the left side of the body, then mirror the line to create an illusion of depth. Use the pen to fill in Squirtle's squiggly mouth line and the two slashes for the nose.
Select the circle tool and click and drag to center two ellipses for eyes. Switch back to the pen tool and add half moon reflections. Finish Squirtle with the details on the stomach of the shell.