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.
But the troll-dragon having been eliminated and the bear story selected as the one to be used in connection with Hjalti's display of his newly acquired bravery, for which purpose it is, indeed, on account of the presence of the king and his court, more appropriate than for giving Hjalti an opportunity to imbibe secretly an animal's blood, another story had to be devised to account for Hjalti's strength and courage.
But a bear is a real, not an imaginary, animal, and King Hring took a creditable part in the effort to dispatch it. Hence, this story was substituted for the story about the troll-dragon and adapted to the circumstances, King Hrolf himself taking the lead in the hunt and thus acting in a manner that seemed more to his credit than the way he acted in regard to the monster in the saga.
Among the Icelandic legends collected by Jón Arnason is a story which, in certain important particulars, is very much like the story about Bjarki's fight with the troll-dragon. A portion of it is as follows: "A man named Gudmundur lived once upon a time at a farm called Silfrúnarstadir, in the bay of Skagafjördur.
The troll-dragon has been eliminated, but so great, in the rímur, has the strength of Hjalti become that it now equals that of the very monster, the troll, which, in the saga, he feared to such an extent that it rendered him pitiable in the extreme.
And however insistent one may be in maintaining that the author has introduced an element that is not recognized saga-material, it must be admitted that he has so skillfully fused it with good saga-material that it is not probable, as the rímur show, that contemporary readers found any fault with the episode. But does such a monster as a troll-dragon have any sanction in folk-lore? Yes, it does.
Bjarki must receive credit for his great achievement in killing the troll-dragon; he must receive credit for having made a brave man of the cow Hott; Hott must give proof of his newly acquired courage; his change of name must also be made, and, as is most appropriate, it must result, and result naturally, from the deed by which his courage is displayed.
Grendel is a hall-attacking monster; the troll-dragon is not a hall-attacking monster.
In view of the fact that the troll is a troll-dragon, that the eating of its heart associates the episode very closely with the similar episode in the Volsungasaga, and that the rímur magnify Hjalti's strength by saying that it is equal to that of a troll, it is hypercritical to say that the saga here contains an incongruous element.
The troll-dragon, which is an unusual creature, has been supplanted by the more conventional creatures, a wolf and a bear; and by the employment of two animals, the necessity of causing a dead animal to be propped up and be apparently killed again, is avoided.