But does such a monster as a troll-dragon have any sanction in folk-lore? Yes, it does. It is characteristic of Norse folk-lore to ascribe troll-like qualities to beings about which there seems to be something supernatural, such as invulnerability. In one of Asbjörnsen's tales, there is a story about a troll-bird, told by a man named Per Sandaker, who "was supposed to be strong in stories about troll-birds." In the story referred to, there is a woodgrouse (tiur) which has become known as a fabulous animal (fabeldyr) throughout the whole neighborhood. "One might just as well shoot at a stone,' said Per, with the greatest conviction"; for he had shot at the bird and made the feathers fly, without being able to injure it. Later, on the hunting-trip on which Per was telling about the bird, he and a companion came across it. "Now he is out again, the old fellow," said Per; "there is no use in the wide world to shoot at him, one might just as well shoot at the clouds." The men maneuvered for a position; and Per's companion, who is telling the story, says, "My gun was raised, and the mighty bird tumbled down head first." Per picked it up and examined it and declared that it was the troll-bird; he could tell it by the beak. On the same trip stories were told about troll-hares that for a time had escaped uninjured but had finally been killed.[64] Panzer[65] and others have called attention to the discrepancy between the statement that the monster in the saga is said to be invulnerable, and that it is nevertheless killed. In the story from Asbjörnsen's tales we have the explanation. The troll-animal seems to be invulnerable until some one appears who has the requisite skill or strength, or a combination of both, to dispatch it; and it might be observed that Bjarki paid no more attention to Hott's statement about the invulnerability of the troll-dragon than Per's companion paid to Per's statement about the invulnerability of the troll-bird.