in the Warhammer
universe, an ancient race of giant amphibian superbeings.
They are largely responsible for the state of the World as it is today, having:
created the warpgates at the two poles
created all existing races on the planet through breeding
placated the creatures of the Warp
travelled the universe doing similar things to other planets
By some colossal error, they also brought about the destruction of the warpgates.
the entities known as Chaos Gods to enter the material universe,
the creation of two continent-sized radioactive hellholes known as the Chaos Wastes
the corruption of early Man, Dwarfs and Elves.
the creation of the condensed warpstuff known as Warpstone
the almost complete extinction of their race, with the exception of their degenerate descendants, the Slann
The Old Slann also play an important role in galactic history; in the WH40K
worldview the Slann's catastrophe occurs simultaneously on all Slann worlds in the galaxy, and has been postulated to have created The Eye of Terror