A mastodon is a large, thick-skinned, herbivore that is not very common in the dungeon.
To be precise, mastodons are a group of species. Not a single species. While the mastodon does resemble the modern elephant, the modern elephant is not a direct descendant of the mastodon.
Any large, elephantlike mammal of the genera Mammut, Mastodon,
etc., from the Oligocene and Pleistocene epochs, having
conical projections on the molar teeth.
This page is based on a spoiler by J. Ali Harlow.