Answer:
A mysterious, fantastic creature, It has one defining feature, And for humans at their worst, In their eyes it's just a horse
It's black and every time it speaks it says its name.
I have eight to spare and am covered with hair.
I'm a lion with a human head. Guess my Riddle or you'll be dead.
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 do you purposefully put lots of in and on your body, but run away from when you encounter it outside?