Stone-trolls are huge trolls, slightly bigger then Hill-trolls, who turn to stone in direct sunlight. In The Hobbit, Bilbo and company met a group of Stone Trolls known as Tom, Bert, and William. Gandalf defeated these trolls by tricking them into staying in the clearing until the sun came out, when they turned to stone.
The stone trolls
"Dawn take you all, and be stone to you!" said a voice that sounded like William's. But it wasn't. For just at that moment the light came over the hill, and there was a mighty twitter in the branches. William never spoke for he stood turned to stone as he stooped; and Bert and Tom were stuck like rocks as they looked at him. And there they stand to this day, all alone, unless the birds perch on them; for trolls, as you probably know, must be underground before dawn, or they go back to the stuff of the mountains they are made of, and never move again. That is what had happened to Bert and Tom and William.
"Excellent!" said Gandalf, as he stepped from behind a tree, and helped Bilbo to climb down out of a thorn-bush. Then Bilbo understood. It was the wizard's voice that had kept the trolls bickering and quarrelling, until the light came and made an end of them.
Hehe these look good you can even see a bit of blood under one !! They were filming ''The Hobbit ' when I was in NZ last month around Matamata area but didn't have time to go & watch unfortunately !
