Behemoth

Behemoth is a classification given to a number of species of reptilian creatures that were created by the Primordials to be living weapons during the Dawn War . They were a rarity, inasmuch as they were actual living creatures that the Primordials created from whole cloth, rather than existing creations of the Gods that were twisted and reforged.
The majority of the Behemoths were destroyed in the Dawn War, but some show up in remote places, such as the Feywild and the Underdark. Rumors persist of a lost land where Behemoths are found in great numbers, but no one can say where it may lie.