How to use exaggeration in creature design

Using exaggeration in your creature design, or even in character design is a little secret that will help you communicate your idea and add interest to your design greatly. It’s that big hooked nose with a mole on it that tells you someone is a witch. The big horns on a creature communicate that it can be a hard hitter. Flashy colors that communicate that the mating season has started or that the creature is toxic. You name it, everything that is ‘extreme’ in shapes, colors, contrasts, and so on, could be a tool. So, how do you use that properly?