Guardian Dragons have large shields on the end of their tails. Although the shields appear to be heavy, they are light, yet nearly unbreakable. Guardian Dragons use their tail-shields, as well as their wings, to deflect attacks and protect others. Often, they will guard the eggs and hatchlings of a nest while others are away. They are generally peaceful, and will not retaliate unless necessary. They have no need to forage or hunt, as they are fed by those they protect.

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.

Annabeth was given the sign of the guardian as a child.  For a while, she didn't know what it was for.  But one day, her entire village was surrounded by darkness, blocking out the sun.  Dragons scattered in fear, but Annabeth somehow knew what to do.  She flew up to the sky, the guardian sign blazing and said "Mitne di wer Sargt, release douta vers!" which meant 'Light of the Guardian, release your power!"  The sign blazed brightly, destroying the darkness and saving the land.  She flew down and landed among the dragons, all of them cheering.  Annabeth smiled.  She knew now what the sign was for.