The Bull earlier symboised Autumn, a rainy, fruitful green year follows its slaughter. The snake for the Mithras was symbolical for the Cosmos and the Zodiac. The Snake is a path, over which the sund and the moon move. The sun and the moon follow a goal in their orbits. Hence the Zodiac is a symbol of time.
Many scientists describe the snake as a symbol of movement and of development.
If a snake stings a Yezid, he is healed only through prayer of a member of this caste and his saliva on the snalebite's wound. The scorpion in the mithraistic animalworld symbolises the sun. The snake goes into the sun-orbit on 23. One can definitely state, that the Yez. have taken over the Bull, the Snake and the Scorpion, not from the Zorasthrianism, but rather from Mithraism. The snake and the scorpion are described in the Avesta as harmful animals - sent by Ariram.