Frilled Dragons are smaller than most other breeds, but when threatened, they stretch out their wings and frills to appear larger. They generally do not like to fight and prefer hiding to confrontation. Frilled dragons live in small groups and often band together to scare off potential threats. Males also use their frills as a way to attract mates, with those displaying the “best” frills being more likely to breed.

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.

Frillix Celo was born from one of the three frill eggs that appeared in Krystalix's cave. Frillix is the eldest of the three frills (the other two being Vizt Spica and Curlitz Sennite), therefore is more protective of the two younger ones, although she can entrust Amethyst Barrage with them. Being smaller than the other dragons who reside in the cave, she constantly feels like she should be wary of them, but slowly she is starting to fit in and trust the other dragons. Yet she still protects the other two frills fiercely, and in fights she doesn't trust the other residents of the cave with them.