Swallowtail Dragons are graceful and quick flyers, much like their namesake bird. They are capable of precise aerial acrobatics, and can reach very high altitudes. Because of this, humans observing these dragons are often astonished at how large they are when confronted up close. A Swallowtail’s diet consists of insects and small mammals plentiful in temperate forests. These dragons are also made remarkable by their paper-thin wing membranes, which allow light to pass through, creating an astonishing effect on starry nights.

Dragons are highly-intelligent reptilian creatures that—from a human perspective, at least—appear to live forever. Many different varieties of dragon exist, each with their own unique qualities, habitats, and behavior. Adolescence in dragons is usually marked by the growth of a hatchling’s wings, although not all breeds of dragons grow wings and some breeds have other traits that indicate the beginning of maturation. In Galsreim, dragons and humans coexist peacefully.

Cardiem was named after the phrase "Carpe Diem" in ancient tongue, which means "seize the day". This phrase also seems to represent his personality quite well. He never really thinks about the future, and he always puts maximum priority on enjoying each and every moment to its fullest. He detests boredom, and will get supremely ticked off whenever someone interrupts his fun. His personality is a difficult one to get used to, but his friends have found him to be oddly lovable once they did. He is best friends with Laetora, and they are always going on all sorts of adventures together, but Cardiem wants their relationship to become a little more... intimate. However, he lacks the necessary courage to speak his mind to her.