Greatwyrm

Greatwryms were dragons that had achieved godlike abelites, approaching the powers of the aspects of Tiamat and Bahamut.

Abilities
Though exact powers varied from each type of greatwrym, in general all greatwyrms had abilities that allowed them to return to near-full strength just before death. Many of their other abilities were more powerful versions of those of normal dragons, with chromatic greatwryms being able to make spears out of arcane power, Metallic greatwyrms being able to drain the energy of foes, and gem greatwyrms having more powerful psionics.

Creation
According to Fizban the Fabulous (one of Bahamuts aforementioned aspects), greatwryms were normally created when dragons of ancient age category ate their "echoes" from other planes or consumed their energies in other ways.

Notable Greatwyrms

 * Sardior's Greatwyrms were a group of five greatwyrms (one of each of the five types of gem dragons) who intended to absorb every one of their echoes with the ultimate goal of coming together and reforming Sardior.