So this is the general process on how I make a Prinny. The following was made in Photoshop, but can be easily made by other means (pencil, other art programs, ect.).

1. Start with two circles. The smaller one will be the head and the lower one is the body. The bigger the body circle the pudgier. Basically my Prinny designs are pear shapes.

2. Add lines showing which way the character is facing and connect the two circles together with a curve. I tend to add the flippers and stubby legs positions as well.

3. Add more details in including the beak that ends up in the middle of the directional lines on the head and add a rough design of where the belly and stitches will go. Added the wings and tail to this picture to show where they would generally be even though the wouldn't really be visible from the this angle.

4. Time to starting smoothing out parts of the character. Stitching on the belly can be whatever design you want. Showing a fatter or bloated Prinny would be indicated by bent stitching. Using the warp command in Photoshop makes bends easies but will usually makes the lines look off so you made have to retrace it to clean it up.

5. Following your earlier rough work color the Prinny in and your done.

6. Six is an optional and a bit more accurate version of the character (I usually do it this way). The white belly part because that portion is usually closer to the beak. Adjust the flippers as needed when doing this.