Utterly Mad

Yes, durgons are not reptiles. they are fish.

Spoiler (hover to show)

For the most part, dragons are reptiles. The Europian dragon is a creature with four legs and a pair of wings. They also have the intelligence of an animal. The Asian dragon is a serpentine reptile with four legs and no wings and are very intelligent. The word "dragon" comes from the greek "drakon" which meant something like "water serpent."

The dragons in skyrim are technically intelligent wyverns with no stingers.

and technically "lich" is just the german word for a corpse, slightly misspelled. Lot's of dragon myths and legends, only one "lich" myth/legend.