Some dragons have very bird-like attributes, such as feathers. Also, some dragon myths have alternate versions, in which the dragon is a type of bird, showing how similar they are in some instances, e.g. Tiamat is sometimes depicted as a lion-headed storm-bird, as oppose to a dragon. It is possible that in the past exotic birds were mistaken for dragons. As people had not seen such creatures before, they could well be misinterpreted as some some kind of mystical creature. For example, a fair number of medieval dragons had roundals on them, like a peacock's tail. Or, a familiar bird may be seen so briefly, that it is misidentified. One possible origin of Toltec/Aztec feathered serpent myths (such as Quetzalcoatl) is the Resplendent Quetzal (Pharomarchus mocinno). This bird has extremely long tail covers, which can make it look a bit like a flying serpent, especially combined with it's striking metallic green colour. To give an idea of the length of the tail covers, an average bird is 35cm long, and it's tail covers 60cm (note that the tail covers are not part of the tail). Iterpreted as some some kind of mystical creature. For example, a fair number of medieval dragons had roundals on them, like a peacock's tail. Or, a familiar bird may be seen so briefly, that it is misidentified. One possible origin of Toltec/Aztec feathered serpent myths (such as Quetzalcoatl) is the Resplendent Quetzal (Pharomarchus mocinno). This bird has extremely long tail covers, which can make it look a bit like a flying serpent, especially combined with