Icarus was a planet that formerly occupied the orbit of what is now the asteroid belt of the solar system. It was was once inhabited by a mysterious race known as the Cthonians.
Icarus was slightly larger than Earth, and further from the sun, but it maintained an Earth-like environment due to its thicker atmosphere, abundant water, and a larger, more active molten core. Although rich in thermal energy and heavy minerals, Icarus' crust cooled sooner than Earth, and life began in its oceans long before it did in the still forming humid seas of Earth. Geothermal heat made the planet a hothouse despite the lack of solar warmth, and a thick cloud layer permanently covered the equatorial areas. Harsh and volcanic, the equatorial continent was a barren and hostile area covered with acid swamps and corrosive fogs, home to vicious and deadly beasts.
The Northern continent, unlike the equatorial areas, was clear and much more Earth-like.? Sandy beaches gave way to rolling plains, dense forests, and majestic mountains topped with snow. Life was abundant and varied, consisting mostly of large herbivores that fed on the rich vegetation. Predators were few and life flourished in every part of the land, although humans tended to stick to the high ground.