An animal tattoo can be anything from a household pet, such as your dog or cat, to a power animal, such as a bear or tiger. Each animal denotes different qualities that you may have or qualities you strive to achieve. Household animals are most commonly memorial tattoos, honoring your particular pet, while power animals are more representative of a certain prowess or strength. Your tattoo can either be of the full animal body or just the head of one for a tattoo that takes up less space.
A hair cross-section tattoo is a patch of skin tattooed to mimic the appearance of animal fur. The cross-section can have other attributes, along with color, such as spots to resemble a leopard and strips for a tiger. The cross-section can be as large or small as you want, though the patch should be large enough to adequately display the unique patterns of the fur. You can also have the patch in the shape of a paw print to take the design a step further.
The yin yang is an Eastern symbol of harmony between opposing elements. They are most commonly drawn as black and white, but artistic license affords you the chance to use other colors and textures, as well. For a hair yin yang, leave one side empty to depict the human side as your on skin while the other side can be an animal's fur. It will portray duality and harmony between humans and animals in a new take on an old-fashioned design.
A script tattoo is a collection of letters or numbers. For a hair script, either you or your artist can design the appropriate characters for your tattoo in a font that appears to be sprouting animal hair or fully covered in it. Adding hair to letters and numbers increases the detail significantly, so the script, itself, should be somewhat limited (one or two words) to keep from appearing jumbled.