The Monster Manual describes the origin of the Oblex as “a slime capable of assaulting the minds of other creatures. These pools of jelly are cunning hunters that feed on thoughts and memories.”

The Monster Manual describes Liches as “the remains of great wizards who embrace undeath as a means of preserving themselves. They hunger for long-forgotten knowledge and the most terrible secrets. Because the shadow of death doesn’t hang over them, they can conceive plans that take years, decades, or centuries to come to fruition.”

The Monster Manual states that “tens of thousands of years ago, the elves were divided, with those of benevolent disposition battling those that were selfish and cruel. The war among elvenkind ended when the good elves banished their malevolent kin to the subterranean depths. Here, in the lightless caverns and endless warrens of twisting passages, the dark elves — the drow — found refuge.”

The Monster Manual states that Dragon Turtles are “among the most fearsome creatures of the oceans. As large and voracious as the oldest of its land-based dragon kin, a dragon turtle strikes with its deadly jaws, steaming breath, and crushing tail.”

The Monster Manual describes jinni as “rare elemental creatures out of stories and legend. Only a few can be found on the Material Plane. The rest reside on the Elemental Planes, where they rule from lavish palaces.”