Feisty and energetic, Whiptail Dragons pride themselves on their speed and agility. It is not unusual to see several whiptails racing each other. Though fragile, they can easily evade attacks with their superior speed, and often use their long tails as a weapon, giving rise to their name.

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.

Thoos, whose name means 'swift', is a deep chestnut brown dragon with electric blue markings and sky blue eyes. He is the first of the fifth clutch of dragons and was taken from the main cave. Swift as any whiptail, Thoos prides himself in his speed and is willing to race anyone who wishes to. He can often be found racing with Lachne amongst the fields. Thoos also finds a passion in sparring; although he is not very powerful, he uses his speed to his advantage and uses his tail to trip opponents up. However, he only fights for fun, never on terms of aggression or anger. Thoos is always eager to make friends, although he does have a habit of bragging at times, and he often enjoys including his friends in racing competitions. Thoos is very bright and optimistic, trying to see the best out of things and fellow dragons rather than their worst. He does not try to run away from his problems, but would rather face them head on and deal with them without trying to hide himself or his faults.