Answer:
Known as a great deceiver, It is evil's incarnation, Once used for veneration, The root of all procreation. All you can do is shiver, When it begins to slither.
What scientists might call your pooch.
A mysterious, fantastic creature, It has one defining feature, And for humans at their worst, In their eyes it's just a horse
What is that which, while it lives, constantly changes its habit, that is buried before it is dead, and whose tomb is valued wherever it is found?
What lives where it cannot breathe and has a hole in its back
You use it between your head and your toes, the more it works the thinner it grows.