These are 2 Nidhogg texture mods, but they do not replace the Nidhogg.
Saphira uses the same texture as the Thunder Dragon in AoM Dragons UE, with the addition of an eye to the texture. You should have given credits for that texture.
Thorn's texture looks like it was made in MS Paint. :(
BTW, the instruction text file says something about a Yu-Gi-Ho dragon.