I can roar but don't have a mouth.
I can cry but don't have any eyes
I am really good but bad sometimes.
Without me, all will die.
What Am I?
Either Rain Cloud Or Air
Explanation
=== Rain Cloud ===
I can roar but don't have a mouth: Thunder
I can cry but don't have any eyes: Rain
I am really good but bad sometimes: Storms
Without me, all will die - Obvious
=== Air ===
I can roar but don't have a mouth: Wind
I can cry but don't have any eyes: Moisture
I am really good but bad sometimes: Hurricanes
Without me, all will die - Oxygen.
