|Loren, Lu'ad, Illgad
|60% nitrogen, 29% oxygen, 11% other gases
With high oxygen levels, the weather on Lethun is extremely volatile. Lethun's year is longer than its day due to the gravitational tugs by its three large moons.
When the sun sets, enormous temperature differences create torrential downpours. When these downpours stop, the landscape plunges into a long winter which does not end until the sun rises again.
The size and orbit of Lethun's moons cause major tidal waves across the entire planet. The planet has a seven-day cycle of flooding, where the oceans rise 300 feet in large regions across the planet. The constant rising and lowering of the ocean has caused significant erosion; there are virtually no mountains on the planet. The higher elevations tend to be in the shape of large mesas or cliffs.
The landscape changes literally overnight as enormous glaciers form. During the daylight, these glaciers melt and stalks growing from the ocean floor spring upwards to life.
Most life is adapted to the long seasonal cycle. Plants overcome this through alternation of generations, hibernation, or by leaving seeds behind until the night passes. Animals often adapt to seasonal changes, and many are r-strategists.
Many creatures also have a third eye on the backs of their heads used to assist them in detecting seasonal changes and to prepare for storms.
- Beanstalk - An enormous plant that starts from the ocean floor then grows high above the surface. Very often, beanstalk forests are found clustered together. These plants became the homes of Klymu.
- Nomadbloom - A plant that floats on water.
- Floating algae - Clumps of dark green plant matter that floats on the ocean's surface.
- Spikecoral - A species of coral armed with poisonous barbs
- Kelptongue - An aquatic plant-animal hybrid that rests on the sea floor. It has a round base with studded teeth pointing inwards, while it has large kelp-shaped "tongues" floating upwards to attract prey. Any unfortunate victims will be caught by its tongues and dragged down to its base where they are consumed. The tongues themselves are also photosynthetic allowing additional energy to be gathered.
- Ashwood - A native plant to the Arid Lands with a deep root system. After burning away, it can quickly regrow and replenish the burned down area salvaging nutrients from the ashes.
Swamps and Ocean
- Klymu - The intelligent, civilized species of the planet.
- Sailorfish - An invertebrate that floats on the surface. A flap of skin above water allows the wind to control where it goes.
- Decikrab - A giant ten-legged crab-like creature with four claws. It lives on top of low elevation mesas covered in sand. It is considered big game by the Klymu.
- Hummingull - One of the few avian species on Lethun. Its wings flap 200 times every second to remain aloft in the high gravity world. As a result, it is on the search for food constantly due to its high metabolism. It has a spear-like beak to pierce fish from the water. Sometimes, it may get caught by a Kelptongue.
- Abyssal Sandhider - A massive, slow-moving creature that buries itself in the sea floor. Despite being the largest animal on Lethun, they are gentle giants. It feeds on zooplankton by catching them with its tendrils along its body, while it also shares a symbiotic relationship with some deep-sea coral.
- Lancefish - A large carnivorous fish with a long spear-like structure at the tip of its nose.
- Fleshrunner - A pink, four-legged herbivorous land creature with similar anatomy to an antelope. Females' only form of defense is running, but males have large horns. Fleshrunners are among the fastest of Lethun's land creatures capable of constantly running at 70 mph.
- Fleshchaser - The carnivorous counterpart to the Fleshrunner having a similar anatomy. These mammalian carnivores can run at top speeds of 80 miles per hour though in short bursts. They are often used as hunting pets.
- Ferrupack - A four-legged giant herbivore with an incredibly tough hide made of unrefined iron. They are Lethun's largest land animals at 5 meters tall and can be found trudging across the plains. The creature also has two large horns and four tusks. Ferrupack are often hunted for their horns, but the creature itself is a dangerous foe. If threatened, a Ferrupack will charge straight on and maul its opponent.
- Ironhunter - A four-legged carnivorous reptilian creature with the strongest skin in Lethun. Their plated hide contains large traces of iron giving them a shiny, metallic appearance. They compete for the top of the food chain with the Fleshchaser, and the two species will prey on each other. Though it cannot run fast, Ironhunters have the deadliest bite in the entirety of Lethun, capable of a force of 450,000 pounds per square inch (though ironically, an Ironhunters' mouth can be sealed, completely shut with several layers of duct tape).
Lethun's moons are rich with minerals, especially iron and iridium. Loren is a mostly barren rock with great limestone formations. Lu'ad consists of a single ocean, appearing green due to a high concentration of algae. Illgad is greyish, black with a thick atmosphere of dust clouds. Since the Klymu have achieved space travel, Loren has become a primary mining area.
Illgad on the other hand is notorious for its storms and toxic atmosphere. The moon is incredibly dense with unusually high gravity for its size making mining next to impossible. Illgad's unusually high density leads some to believe it is artificial, but close examinations still remain an impracticality. Illgad was later discovered to be a LUCIS node posing a threat to the existence of the Mizani Empire. As such, Lethun was one of the first compromized planets when LUCIS awoke.
Los'gi • Lethun (Loren, Lu'ad, Illgad) • Gors • Nwy • Ormaw • Rhemaw • Peltern