Dragons (or wyrms) were very powerful and magical creatures. There were several types of dragons, the most common of which were chromatic and metallic, which were evil and good respectively. They were an ancient race. Few species that still exist can claim longer lineage. Dragons were the bane of the creator races of Toril; their line was so old, they had their own realm during the first recorded exploits of the elves. In recent times, the dragons of Toril were nearly all recluses or at the very least secretive as to their true nature, living among other species in polymorphed form.
"Dragons? Splendid things, lad – so long as ye look upon them only in tapestries, or in the masks worn at revels, or from about three realms off"