Trolls live under bridges (as in the Norwegian fairy-tale Three Billy Goats Gruff) or under ground. They are often malevolent towards humans and will raid villages and abduct women and children. Trolls' primary weaknesses included their lack of intelligence, a dislike of loud noises (they can be driven away by ringing church bells), and their vulnerability to sunlight. If a troll is caught in direct sunlight they will turn to stone.
The following comic poem by acclaimed fantasy author J.R.R. Tolkien tells of an encounter between Middle-Earth hero Tom Bombadil and a grave robbing troll...
"The Stone Troll" by J.R.R. Tolkien
Troll sat alone on his seat of stone,
And munched and mumbled a bare old bone;
For many a year he had gnawed it near,
For meat was hard to come by.
Done by! Gum by!
In a cave in the hills he dwelt alone,
And meat was hard to come by.
Up came Tom with his big boots on.
Said he to Troll: 'Pray, what is yon?
For it looks like the shin o' my nuncle Tim.
As should be a-lyin' in the graveyard.
This many a year has Tim been gone,
And I thought he were lyin' in the graveyard.'
But what be bones that lie in a hole?
Thy nuncle was dead as a lump o' lead,
Afore I found his shinbone.
He can spare a share for a poor old troll,
For he don't need his shinbone.'
Said Tom: 'I don't see why the likes o' thee
Without axin' leave should go makin' free
With the shank or the shin o' my father's kin;
So hand the old bone over!
Though dead he be, it belongs to he;
So hand the old bone over!'
'For a couple o' pins,' says Troll, and grins,
'I'll eat thee too, and gnaw thy shins.
A bit o' fresh meat will go down sweet!
I'll try my teeth on thee now.
Hee now! See now!
I'm tired o' gnawing old bones and skins;
I've a mind to dine on thee now.'
But just as he thought his dinner was caught,
He found his hands had hold of naught.
Before he could mind, Tom slipped behind
And gave him the boot to larn him.
Warn him! Darn him!
A bump o' the boot on the seat, Tom thought,
Would be the way to larn him.
But harder than stone is the flesh and bone
Of a troll that sits in the hills alone.
As well set your boot to the mountain's root,
For the seat of a troll don't feel it.
Peel it! Heal it!
Old Troll laughed, when he heard Tom groan,
And he knew his toes could feel it.
Tom's leg is game, since home he came,
And his bootless foot is lasting lame;
But Troll don't care, and he's still there
With the bone he boned from its owner.
Troll's old seat is still the same,
And the bone he boned from its owner.
Above:This stone, photographed in Hamarøy, Norway, with its roughly man-like features could be explained by folklore as a troll petrified by sunlight, like the one's in Tolkien's The Hobbit (1937).
Sources:Spirits, Fairies, Leprechauns, and Goblins: An Encyclopedia by Carol Rose (1996) and The Tolkien Reader (1966).