Balloon Dragons are so named because they are filled with a gas that makes them almost lighter than air, similar to balloons. However, they are not prone to bursting, as they are covered in tough skin and can deflate themselves if necessary. In addition, they generally are slow moving. They use their gas bladders to float to the tops of trees, where food is more abundant. They can shift their weight from their backs to their fronts, allowing them to reach leaves and fruit.

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.

Emmet Brickowski is about as "normal" as a balloon dragon can be. He likes everything everyone else likes. He's a good team member, but his efforts to be pleasant and fit in with the others makes him rather dull, in their eyes. He is so unremarkable that his peers have very little to say about him, let alone remember him by. He lives alone in his cave; his "friends and family" are a potted plant and broom. The only way for Emmet to get any attention is to be thrust into adventure by accident, and even so, people probably won't think he'll amount to anything.