Dragons

Dragons are ancient, mystical creatures. Their bodies are filled with more magic than any human could hope to have, and oftentimes they control a certain element perfectly and powerfully with that power. Often they appear reptilian due to their scales, but every now and then a dragon species could be found that seems to have more mamalian skin.

Appearance
Dragons are impossible to classify by appearance, as they can vary wildly even within the same "species". A prime example of this is in the "Fairy Chapter" where all dragons will look drastically different depending on the element they control.

However, generally, dragons will appear similar to various reptiles.

Magic
Most - if not all dragons are known to possess very powerful and potent magic. Often this magic is represented by some kind of element or spell type specialty, though not always. The classic image of a dragon breathing fire is an example of this magic, though a lesser-known example is dragon flight. Dragons don't have the right body shape to properly be lifted by their wings, so they actually fly with a combination of their wings and magic (or pure magic for serpentine "eastern" dragons that lack wings altogether).

In Our Eternal Story
Dragons of various species have been encountered along the course of the story, but the main Dragons are the baby dragons owned by Nero, Crystal, Lolita, Jackie, Ling, Tomoyo, Himura, Izumi, Mavis, and Zeref. They all formed familiar contracts shortly after their births, and can be "aged up" using a spell to aid in battle. Otherwise, they remain at the size of small cats.

Though Snow is often said to be a "Crystal Dragon" by others, he is actually a kind of nature spirit in the form of a crystal serpent.

Dragon-Type Pokemon
Nero and Lolita each have a few Dragon-Type Pokemon from their time in the "Pokemon Chapter". These Pokemon are considered dragons in a sense and are often counted as such, though they aren't exactly the same thing.