Thunder Dragons are the masters of electricity. Their wings gather energy as they soar through the clouds, and when they clap their wings together they can create devastating arcs of lightning. They can stay airborne nearly indefinitely, landing only to sleep and breed; they catch their prey from the air and take moisture from the clouds. A thunder dragon’s roar is considered to be an omen of misfortune.

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.

You'll Be Sorry is a terror to behold, although he is rarely seen.  Living in storm-clouds causes his wings to collect a huge amount of electrical energy; the low-frequency buzz his body makes as he tears through the sky can be heard often in poor weather, and creatures take this as a sign to stay undercover lest they be spotted by the temperamental Thunder.

Sorry earned his name before he chose Preto Osso's clan to scope for a mate. His previous mate and first clutch of eggs were killed by a nomadic Vampire whilst Sorry was catching deer; his fury and grief upon returning to his mate's nest was heeded for many miles around as he destroyed the mountainside with stored electricity upon the nest was perched, accompanied by a tumultuous roar and a telepathic message to all dragons in the area, hoping to reach the murderer: "You'll be sorry!"

Sorry is entirely unaware that the culprit was the Vampire Rottingham, who wanders the fringes of Preto Osso's territory, keeping his crime a secret.