- For the multiplayer map, see Sarathos Swamp.
- “ I've seen Alien Monkey poop prettier than this place. ”
- ―Merc describing Sarathos to Ratchet and Green.
Sarathos was an alien swamp planet with a very gaseous atmosphere. Sarathos was inhabited by Leviathans; the monstrous, and very aggressive scorpion-like beasts that lurk in the swamps. The average Leviathan's monstrous nature was matched only by the King Leviathan, a much larger and more dangerous Leviathan that resided in a combat arena built by the Vox construction team.
Like many other planets in the Shadow Sector, Sarathos was used by Gleeman Vox as a DreadZone challenge course. The challenge course revolved around getting into the combat arena where the King Leviathan resided and destroying it. Ratchet was assigned to this challenge and survived his encounter with the Leviathan horde.
Apparently, Sarathos is home sentient beings known as Sarathosian Swamp Jaggas.
Jellyfish-like creatures could be seen at the edges of the map, flying through the air. Its appearance is similar to those found on Kortog. A planet that looks like Sarathos is seen in the sky from Mukow.
Sarathos has always been a hellish world, which encouraged Sarathos to remain visited as little as possible. The only known activity by sentients were the local Sarathosian Swamp Jaggas, which were native to Sarathos.
That all changed; however, with DreadZone's arrival, who used Sarathos as a battle course for gladiators. Ratchet, Merc and Green were forced to traverse the swampy on a dangerous hunt for a King Leviathan. After battling DreadZone gladiators, Shriekers and Leviathans, the met the King Leviathan at last in a small arena. The trio managed to kill it and thus succeed in the Sarathos death course.
Sarathos being a swampy planet is home to many bioforms, most of these are hostile to Ratchet, Merc and Green. Here are the creatures that are seen are Sarathos and some that are most likely native to this world.
- Shriekers: Shriekers are small scurrying pack hunters. A single Shrieker's threat level is low and a group of them is still not that much of a threat. However, they tend to hang around by deadly Leviathans, and they can get in the way during critical moments. They also jump out of the swamp waters at times.
- Leviathans: Leviathans are massive predators with stingers that shoot natural laser beams. They are often found with Shriekers nearby. They will pop out of the swamp waters or Sarathos slime holes, though sometimes are seen patrolling the fields of Sarathos. Sometimes they will stay submerged under the Sarathos slime puddles and raise their tails to blast their foes with. Leader Leviathans are known as King Leviathans.
- King Leviathans: King Leviathans are even more massive than regular Leviathans. While they have the same attacks as normal Leviathans, they are much more hardy thanks to the Dreadzone armor they wear. The King Leviathan on Sarathos appears to attract endless Shriekers to the fray when fighting him.
- Sarathos Swamp Jellyfish: A harmless Jellyfish like creature with a muddy brown Spherical head with what appears to be extremely dark yellow spots going around its head and four tentacles sticking out from under head. It can be seen floating in and out of the oceans of Sarathos.