Answer:
Black we are and much admired. Many seek us if they are tired. We tire the horse, and comfort man, and turn White when we've fulfilled your plan.
Though desert men once called me God, today men call me mad. For I wag my tail when I am angry. And growl when I am glad.
My first keeps time, my second spends time, my whole tells time.
A dragon's tooth in a mortal's hand, I kill, I maim, I divide the land.
What must be in the oven yet can not be baked? Grows in the heat yet shuns the light of day? What sinks in water but rises with air? Looks like skin but is fine as hair?
A word of five letters, Upside down is the same, A shark does this, But itβs not to blame. What is the word?