Answer:
I drive men mad for love of me. Easily beaten, never free.
Vikings use this for warmth.
It is destruction made out of thin air, You hear it howl and give a prayer, Through barns and houses it will tear. It is a deadly funnel, Of violent and twisting air.
I grow where no flower grows, where no light touches the walls, up or down, that I don't care, was here before people were.
Different lights do make me strange, thus into different sizes I will change
As round as an apple. As deep as a cup. All the king's horses can't pull it up.
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?