These are just some of the varying characteristics of some totem animals. Keep in mind that these are not the end-all-be-all of familiars; there are more out there, including "mythical" beings from every culture.
Ant - Industrious and efficient. Those who have an ant familiar, or who ask for the ant's aide in certain ventures are known to be hard workers.
Bear - The Guardian of Mother Earth and Nature. The bear is known to impart courage and physical strength upon those that He chooses to bless.
Cat - The cat is known for a plethora of characteristics; domesticated cats are known to be guardians of the home, as well as wonderful riddlers, along with their cousin, the sphinx. Cats in general are the masters of independence and mystery. Larger cats (the lion, panther, lynx, etc.) have differing characteristics.
Coyote - The original trickster, born out of Native American legend. The coyote brings news in the form of riddles.
Crow - While some cultures would have one believe that the crow brings tidings of death (and perhaps it does), he also brings justice to those that escape its clutches.
Dog - Loyalty in its truest form. It could be just a coincidence, but those people that I have met that believe they were fighters or soldiers in past lives almost always have had run-ins with the Dog-spirit, or have a canine as a familiar.
Dolphin - The Bringer of Happiness through Wisdom. The Dolphin is also friend to those that feel a connection to the endless drumming of the sea and ocean.
Dragon - The embodiment of Fire, the Dragon knows the answer to some of life's mysteries and riches. He is independent, but is also a protective spirit.
Eagle - The Eagle is another harbringer of bravery and courage.
Griffin - The Griffin evokes feelings of fierce, fiery pride. He is the rider of winds, along with his feathered cousins.
Horse - The horse brings with him freedom from constraint, as well as beauty and pride. Horses are also creatures of the sea and moon.
Hummingbird - The Hummingbird is known as the "Jewel of the Gods." His feathers contain the magick of true love, and his quickness and tenacity make this Spirit a fierce warrior.
Lion - Courage. The Lion is the companion of the Sun, and he also invokes the spirit of a protector.
Lynx - The most adept riddler of the feline family, the Lynx is known for keeping or revealing secrets.
Mouse - The mouse has an eye for detail, and those who have the qualities or blessings of the Mouse-spirit are often quiet, yet this silence is the sign of intelligence and knowledge.
Panther - The Druid's companion when he travels to realms unknown to humans. The panther is also a good protector.
Raven - Mystery. The Raven is the companion to Oracles and omens. He is also known as the messenger of the gods.
Stag - The Companion to the Horned God. Stags bring with them the beauty of nature.
Wolf - The Guide to the human spirit. The wolf shows us the beauty and wonder of the natural world.