The existence of spells like Enral's Eternal Youth Spell by the World's wizards has created a class of immortal. Most of these individuals are powerful wizards, so enchanted by their own magic. A few, however, are individuals like Valder the Innkeeper, Karanissa of the Mountains, Esmera, or Gresh, who through their various involvements have been able granted immortality and youth. Irith the Flyer is another non-wizard immortal, though she gained her immortality through her own, now forsaken, wizardry. By far the largest collection of these immortals is the Inner Circle of the Wizards' Guild and the oldest known immortal is Fendel the Great.
While other races are effectively immortal, such as the Spriggans, or, like dragons so long lived as to be considered so by most people, these immortals were, and remain in most ways, human. The vast majority of immortals are still subject to death, being killed in virtually any way a normal individual might- they simply will not die of old age. A few, like Valder the Innkeeper, have additional enchantments which make them essentially impossible to slay.