The Elder Things are an alien race created by H. P. Lovecraft, and introduced in his novella At The Mountains of Madness.

In the story, a team of scientists from Miskatonic University go on an expedition to Antarctica in September of 1930. When they arrive there, they find numerous well-preserved fossils of prehistoric flora and fauna. However, the expedition would change forever when they find one peculiar fossil that doesn't resemble anything from our planet. Naming them after the "Elder Things" from the Necronomicon (unaware that what they found ARE indeed Elder Things), they find out these creatures were the first creatures to colonize Earth, and settled here before Pangaea even split apart.

When they first settled, the Elder Things built underwater cities thanks in part to their amphibious abilities and their tough bodies being capable of withstanding the pressure of Panthalassa (the ocean that surrounded Pangaea). With Panthalassa colonized, the Elder Things slowly started to build more cities on land, and ended up colonizing the whole planet. The are also presumed to have created the first life-forms on Earth, including their amorphous slave race known as the "shoggoths". Other entities were created, being used, at first, for food sources, only to be forgotten and ignored (as long as they weren't dangerous) by the Elder Things, and thus causing life to flourish (eventually leading to the dinosaurs).

When Pangaea started to split apart (approximately 200 million years ago), numerous cites were destroyed by the natural disasters, with the situation only getting worse once other alien races started to arrive, using the weakened state of the Elder Things as an advantage. The alien invaders (presumed to be none other than Cthulhu and his star-spawn) drove the Elder Things back into the ocean, but the Elder Things fought back using their advanced technology. The war ultimately ended when both sides decided to call it a draw, and agreed that the star-spawn rule the land (with the exception of Antarctica, as that was sacred ground for the Elder Things), while the Elder Things rule the sea.

During the Permian Age (sometime 150 million years ago), a shoggoth revolt broke out, inciting a war between the Elder Things and their former slaves. Because the shoggoths are essentially blob monsters, killing them proved difficult, but the Elder Things eventually won in the end, making sure the shoggoths were properly tamed. During the Jurassic Age, the Mi-Go arrived to conquer the Earth, driving the Elder Things all the way back to Antarctica in a war that lasted for 100 million years. And putting the final nail in the coffin, 500,000 years ago, the Ice Ages started, leaving the Elder Things to build one final city beneath the waves of the Antarctic Ocean.