Animals are worshipped in India in many ways: as deities - the elephant - god Ganesha and the monkey - god Hanuman; as avatars - like Vishnu’s fish, tortoise and boar forms and as vahanas - the swan, bull, lion and tiger were all vehicles of major deities and are thus sacred by association. Some animals, like the snake, are worshipped out of fear. Birds such as the crow are associated with the abode of the dead, or the souls of ancestors, while the cow’s sanctity may derive from its economic value. There are also hero-animals, such as the vanaras and animals which were totemic symbols of tribes that were assimilated into Vedic Hinduism.