The so-called Fafnismol, contained in full in the Codex Regius, where it immediately follows the Reginsmol without any indication of a break, is quoted by Snorri in the Gylfaginning (stanza 13) and the Skaldskaparmal (stanzas 32 and 33), and stanzas 6, 3, and 4 appear in the Sverrissaga. Although the Volsungasaga does not actually quote any of the stanzas, it gives a very close prose parallel to the whole poem in chapters 18 and 19.

The general character of the Fafnismol, and its probable relation to the Reginsmol and the Sigrdrifumol, have been discussed in the introductory note to the Reginsmol. While it is far more nearly a unit than the Reginsmol, it shows many of the same characteristics. It has the same mixture of stanza forms, although in this case only nine stanzas (32-33, 35-36 and 40-44) vary from the normal Ljothahattr measure. It shows, though to a much less marked extent, the same tendency to introduce passages from extraneous sources, such as the question-and-answer passage in stanzas 11-15. At the same time, in this instance it is quite clear that one distinct poem, including probably stanzas 1-10, 16-23, 25-31, and 34-39, underlay the compilation which we here have. This may, perhaps, have been a long poem (not, however, the "Lone' Sigurth Lay; see introductory note to Brot af Sigurtharkvithu) dealing with the Regin-Fafnir-Sigurth-Brynhild story, and including, besides most of the Fafnismol, stanzas 1-4 and 6-11 of the Reginsmol and part of the so-called Sigrdrifumol, together with much that has been lost. The original poem may, on the other hand, have confined itself to the Fafnir episode. In any case, and while the extant Fafnismol can be spoken of as a distinct poem far more justly than the Reginsmol, there is still no indication that the compiler regarded it as a poem by itself. His prose notes run on without a break, and the verses simply cover a dramatic episode in Sigurth's early life. The fact that the work of compilation has been done more intelligently than in the case of the Reginsmol seems to have resulted chiefly from the compiler's having been familiar with longer consecutive verse passages dealing with the Fafnir episode.

The Reginsmol is little more than a clumsy mosaic, but in the Fafnismol it is possible to distinguish between the main substance of the poem and the interpolations.

Here, as in the Reginsmol, there is very little that bespeaks the German origin of the Sigurth story. Sigurth's winning of the treasure is in itself undoubtedly a part of the earlier southern legend, but the manner in which he does it is thoroughly Norse. Moreover, the concluding section, which points toward the finding of the sleeping Brynhild, relates entirely to the northern Valkyrie, the warrior-maiden punished by Othin, and not at all to the southern Brynhild the daughter of Buthli. The Fafnismol is, however, sharply distinguished from the Reginsmol by showing no clear traces of the Helgi tradition, although a part of the bird song (stanzas 40-44, in Fornyrthislag form, as distinct from the body of the poem) sounds suspiciously like the bird passage in the beginning of the Helgakvitha Hjorvarthssonar. Regarding the general relations of the various sets of traditions in shaping the story of Sigurth, see the introductory note to Gripisspo.

The Fafnismol, together with a part of the Sigrdrifumol, has indirectly become the best known of all the Eddic poems, for the reason that Wagner used it, with remarkably little change of outline, as the basis for his "Siegfried."