Like the native Americans, it seems that each Slavic tribe had a totem animal that the clan was usually named after. It was considered taboo to kill or eat this animal except for specific religious rituals. Each member of the tribe was thought to have an animal twin, and the death of that twin could cause the death of the tribe member.
(Note: I came across this piece information so long ago, I do not remember where I orignally found it. Hopefully I'll be able to reference this soon.)
The Slavs believed that the world tree was divided into three parts; The roots existed in the realm of the underworld, "Nav", and were where the Zaltys, the world serpent, lived. The main section existed in the mundane world and the uppermost branches reached into the land of the Sky Gods. A magical bird was said to live in the branches. Although the Slavs did have Viking influence, the Slavic world tree belief seems to have its origins in the systems of the Shamans of Siberia and Mongolia. These Asian peoples were said to each keep a tree, usually a linden, near their home and view it as a sort of "telephone" to the other realms.
Some Slavs believed that the Earth was an Island floating in water that the sun was immersed in every evening. At the center of this Island stood the world tree or mountain. The roots of this tree extended deep into the underworld and the branches reached high up into the realm of the sky gods, Irij. No one knows what kind of tree it is supposed to be. Some believe it to be the original tree from whence all other trees were created.
Nav was the underworld, realm of the dead from whence it gets its name. Weles/Wolos, the God of cattle and wealth and Lada, Goddess of springtime were also said to reside here. This is not really surprising, considering that most cthonic deities, such as Pluto, Saturn and Ops were also associated with wealth and that the crops which defined wealth in ancient times, are pushed upward from inside the Earth. Also, Lada would return from the underworld in the spring, similarly to Kore, Persephone and Ostara of the Teutons.
Long ago, when the world was still fairly new, a young woman ventured into the woods to pick mushrooms. In no time at all, the skies opened up upon her and narrowly escaping the rain, she ran beneath a tree, removed all of her clothing, and bundled them up in her bag so they would not get wet. After some time, the rain stopped and the woman dressed herself and resumed her mushroom picking. Weles, Horned God of the forest happened upon her, and asked her what great magic she knew in order to have kept dry during the storm.
"If you show me the secret to your magic, I will show you how I kept dry." she said.
Being somewhat easily tempted by a pretty face, Weles proceeded to teach her all of his magical secrets. After he was done, she told him how she had removed her clothing and hid under a tree.
Knowing that he had been tricked, but had no one but himself to blame, Weles ran off in a rage, and thus, the first Witch came into being.
Musical Selection is Macedonian, Mile Kolarov's "Kavalska ezgija"