PEOPLE AND ANIMALS IN MYTHS AND LEGENDS.

Ancient mythologies describe a time in the past when the boundaries between people and animals were less sharply drawn and beings changed form freely. Animals offered helpful advice to ordinary people in many legends. Generally, those who ignored the animal's advice failed to achieve their goal.
Sometimes transformations between the two different worlds were forced on some individuals by cruel or wicked sorcerers or as punishment for offending entities with authority in the supernatural world. In the case when people voluntarily sought transformation, however, the change was perceived as a sign of power.
In ancient West African and American societies, for example, the believe that each person has a magical or spiritual connection to a particular animal that can act as a guardian, a source of wisdom, or an inspiration, was common. In general, individuals had to discover their spirit animal through a mystical experience.
Traditional African religions had secret societies in which men were believed to take on a leopard's strength by performing rituals that involved wearing leopard skins.
The ancient people of the Northwestern United States and Canada believed and still maintain the belief that each clan or kinship group is descended from a particular animal, such as whale, wolf, or bear. Bears, in particular, were especially close to them. In some of their stories, bears appear as human wearing coats made of bearskins.
In ancient Central America people had the idea  that each person's life is linked to an animal or object (a nagual). If the animal was killed or the object destroyed, the person was supposed to suffer because of it of die as a consequence of it.
In ancient South American communities, particular individuals were carefully chosen from birth (since they carried a birth-mark), to train them as communal healers. They had the ability to act as messengers or intermediaries between the human world and the spirit world with the purpose of restoring the balance and wholeness of an individual or a community. The supernatural abilities that they performed included the power to communicate with animals that helped them through the supernatural realm, or transform themselves into animals. Andean healers  were said to be able to change themselves into jaguars.
The ancient Greeks and Romans believed that the gods could blur the boundaries between different classes of beings. Ovid's Metamorphoses is a collection of Greek and Roman legends about mortals whom the gods turned into animals and plants.
Chinese and Slavic mythologies include tales of people who, under some evil force, turn into werewolves. Chinese and Eskimo tales mention beautiful, seductive women who turn out to be foxes in disguise.In one Eskimo story a woman enters the home of a hunter while he is out. She cooks for him and stays for some time, but eventually she puts on her fox skin and disappears. The well-known fable of Beauty and the Beast is a modern version of the myth of the animal husband whose beastly form cannot disguise his noble soul.
The Scots have stories about silkies -imaginary sea creatures resembling seals that take on human form, marry men and women, and then return to the sea.
Animals fill a wide variety of roles in myths and legends. They are linked to human origins as well as to the origin of the world. They help to shape human existence by acting as messengers to the other world. They can play tricks, symbolize human qualities, and terrorize humans as well.
Animals sometimes appear as symbols of certain characteristics. Common phrases such "brave as a lion" or "sly as a fox" are everyday examples of the practice of using animals to represent human qualities. The dog often appears as symbol of loyalty and the tiger stands for power and vitality.
Some stories have the representation of the dualistic nature of certain powerful animals. Snakes, for example, can be helpful or harmful. The Romans regarded snake spirits as protection for their homes. However, in the Bible, the snake is a treacherous creature. The bull is another animal with a dualistic nature. It can represent either tremendous energy and power or frightening strength. In Celtic myths, the bull was a sign of good fortune and fertility, while in several Greek legends, bulls were associated with death and destruction.
The frog appears in many transformation stories, most likely because it goes through a transformation of its own, from tadpole to frog. Another one that undergoes a physical transformation is the butterfly, which begins life as a caterpillar, rests in a cocoon, and emerges as a butterfly to spread its wings. The Greek word for butterfly, 'psyche' is also the word for 'soul,' and in Greek mythology the butterfly was the symbol of the soul's transformation after the death of the body.