Sweetlings are a small, flightless breed of dragon. They are omnivores who favor sweet fruits and honey, and have been known to go to great lengths to obtain their favorite treats. Their long, prehensile tails allow them to grab onto branches and give them superior balance. Sweetlings are expressive dragons and have a large array of calls to communicate with others. They become very vocal during breeding season and sing long, beautiful melodies to attract a mate. Inquisitive in nature, Sweetlings are known to investigate anything that piques their interest, and are quick to flee if the object of their curiosity strikes back.

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.

Poisoned Heart was hatched into a cave where his kind are unusually villainous dragons. Heart grew up under the guidance of Nightrose, a Sweetling who created candies that were suitable for Valentine's dragons, but were poisonous to other breeds. With a twisted heart, insatiable curiosity, and inventive mind, Heart has worsened the effects of these candies to be even more painful than before. As his kind are associated with these sweets, he also learned to place gifts at a dragon's door, rather than letting his victim ever see that it was the black, skull-flanked Sweetling that gave them the poison. Unlike Nightrose, Heart doesn't keep track of his kills, and rather enjoys relaxing in the forest rather than in a cave, where he is more likely to come across wandering, sweet-loving hatchlings. Those who survive or escape have told of the cruel grin Heart shows as his red-feathered tail flicks candies into his own maw, tempting his victim while knowing he is immune.