The game features a character customisation system that allows you to express your vision of what the animal should look like. Below is a brief overview.
Your starting point will be through the various presets, with (proto-)feather and scaly options if the animal supports it. These represent the very base of your character, and can be customised to your liking from there by adding your desired patterns and colouring.
Then just customise to your liking and hit "Rise" to start!