Poor kid. Oh well, gotta look at the bright side though he's going to have a peaceful death, what's more peaceful than being devoured while your having the time of your life singing? ;p
Guivre? Hm I don't think so, its skin model was different, this is clearly the "big dragons" model, but I dont remember there being black ones, may be Fafnir/Nidhogg since its grey-ish, or Cynoprosopi, but it was added way later with the Limbus', so i would probably stick with Vrtra or Fafnir/Nidhogg.