Dwarf

Dwarves are the genius of the ground.

For Germans, they come from earth-worm, which had eaten the corpse of Ymir (giant in Scandinavian mythology). Dwarves are the symbol of the ground and grotto, they live in mountains where they hide their forge. Thanks to elves, they build the best weapons like Durandal or the magic spear of Odin-Gungnir.
They are the obscure might which are inside ourself, they are our dark side. They look like monsters.
They symbolise the unconsciousness, or an unverfiable creatures, but invulnerable and they can have reasoning very advanced thanks to his intuition.
Dwarf is considered like secret character because he speak with enigmas but he is a really talkative person.

Dwarf's deformity can be seen like a failure of the nature.

During the Renaissance, small size persons were considered like animals by other people.

Their equivalent in the Greek mythology are the 'cabires'.