Sargasso is a planet featured in Tools of Destruction, the Ratchet & Clank comic series, and Rift Apart, with mentions in A Crack in Time. It is a primordial swampland located in the Verdigris Sector of the Polaris Galaxy, infested with large, deadly creatures such as the grunthors. The planet is also a rich source of gelatonium, with the territorial kerchu operating a gelatonium refinery near its Outpost L51. Prior to the kerchu's arrival, the lombaxes also had a testing facility on the planet.
Ratchet and Clank came to Sargasso in search of the Dimensionator, having seen it in a recored message on Rykan V. Upon arrival, they fought through several kerchu, after first obtaining the Decryptor from the Smuggler, before reaching the remains of the lombax testing facility. There, they met the Plumber, who regretfully informed them that the Dimensionator had long-since been missing.
Sargasso is the biggest source of leviathan souls in Tools of Destruction, which can be traded with the Smuggler for bolts.
Before Tools of Destruction
Sargasso was inhabited by lombaxes, with the Center for Advanced Lombax Research operating a testing facility on the planet for live training and deployment. Among the weapons they tested there were the Dimensionator and the Alpha Disruptor. However, the lombaxes vanished following the Great War.
The kerchu later moved in, constructing gelatonium outposts, including Outpost L51 and Outpost Zulu. Though they were skilled engineers, their territorial nature meant they were hostile to outsiders, with the exception of the Smuggler.
Tools of Destruction
Ratchet, Clank, and Talwyn Apogee found coordinates to Sargasso in a recording by the Center for Advanced Lombax Research on Rykan V, while searching for the elusive "Lombax Secret" (the Dimensionator), and traveled to the planet. Ratchet and Clank arrived safely and met the Smuggler, who offered to trade souls for the Decryptor, a device that could repair the gelatonium-powered robo-ignition pad that Clank's Robo-Wings could interface with. Talwyn, Cronk, and Zephyr, however, struggled to get through the swamp, and were unable to rendezvous with Ratchet and Clank. They were later captured and taken to Zordoom Prison.
After acquiring the Decryptor, in "Search from the Sky", Clank was guided by the Zoni towards the lombax testing facility and arrived successfully, commencing "Investigate the Kerchu Outpost". There, the two fought several kerchu at their gelatonium outpost located within lombax ruins. In the ruins, they found the Alpha Disruptor, as well as the Plumber, who was testing a "revolutionary, high speed, intraplanetary transportation" device. When the duo asked about the "Lombax Secret", the Plumber, who knew of the Dimensionator's true nature, indicated that no device that could wipe out the cragmites existed, before leaving them with a 3 3/4 Centicubit Hexagonal Washer, a key component of the Dimensionator. The interaction led Clank to accurately speculate that the device was in fact used to move the cragmites rather than vaporize them, and the two received a transmission from Captain Qwark suggesting that they return to Mukow. Ratchet continued to obtain leviathan souls from the grunthors on the planet, selling them to the Smuggler for bolts.
After Tools of Destruction
During A Crack in Time, time anomalies were reported on the planet on space radio. On Sargasso, this led to the long-extinct slug guzzling swamp weasels returning and wreaking havoc on the kerchu Outpost Zulu, draining gelatonium dry from the planet.
After Dr. Nefarious was defeated, Captain Qwark's pet War Grok, Snowball, resided in a War Grok reserve on the planet. Sargasso was also stolen by Artemis Zogg during his effort to create the Artemis Galaxy. In All 4 One, the Wigwump, native to Sargasso, was taken to Magnus.
Planet Sargasso was a dangerous and mostly uninhabitable primordial swampland. It was located in the Verdigris Sector of the Polaris Galaxy. This planet was infested with large, deadly creatures like Grunthors who would quickly make a snack out of any unwary explorer. It was also a rich source of gelatonium. The only advanced race known to inhabit the planet were the fiercely territorial Kerchu; however, the Kerchu were not native to this planet. Being advanced builders, they constructed gelatonium drilling derricks, refineries, and plants to take advantage of the large amount of the fuel available. The Lombaxes once had a testing facility for all their latest weapons and gadgets, the most notable being the Dimensionator, hidden in the swamp. Sargasso's environment was, for the most part, divided into patches of land in the large, muddy swamp. These patches of land were accessible only by using the gelatonium fueled robo-ignition pads scattered throughout the swamp to launch the Robo-Wings. Somewhere on Sargasso was a War Grok reserve, where Qwark's pet War Grok, Snowball, resided after Ratchet and Clank defeated Dr. Nefarious.
An alternate dimensional version of Sargasso appears in Rift Apart that is in Rivet's dimension. Like regular Sargasso, it's wildlife include hostile Grunthors and docile Troglosaurs. Unlike regular Sargasso, there are also the docile Speetles and a Pterafoid flyer named Trudi. It is inhabited by very friendly Gelatonium miners referred to as "Morts". Rivet was raised on Sargasso by the Morts. Her and Kit notably saved the planet after Emperor Nefarious tried to destroy it.
Sargasso is a swampland world which is mostly wild outside of a few lombax and kerchu structures. Much of the surface, as seen from space, comprises small continents and sprawling archipelagos, on which are a variety of primordial and insectoid life forms. Among the known wildlife are the buglike anthropods and the flying grubsnuckers. More notably, the world is home to grunthors, Tyrannosaurus rex-like creatures that are large predators holding leviathan souls, and the colossal troglosaurs, saurpod-like creatures that appear mostly docile. Another creature native to the planet was the immense worm, Wigwump.
Outpost L51 was located in an archipalego of islands. The islands are mostly wild, roamed by the dangerous wildlife, while the gelatonium outpost itself is hidden in a structure located just away from one of the islands. Across the islands are little signs of civilization, though robo-ignition pads and other minimal machinery are found throughout them, presumably for the benefit of hunters of leviathan souls. The ruins of the Center for Advanced Lombax Research testing facility remain in a stone structure just a distance from the kerchu outpost.
Behind the scenes
Sargasso is also the name of a sea in the Atlantic Ocean. The sea is often portrayed in popular culture as an area of mystery.
- Tools of Destruction script § "Center for Advanced Lombax Research"
- Tools of Destruction script § "Investigate the Kerchu Outpost (gameplay)"
- Tools of Destruction script § "Explore Sargasso (gameplay)"
- Tools of Destruction script § "Rakar Star Cluster"
- Tools of Destruction script § "Search from the Sky (gameplay)"
- A Crack in Time, 
- Into the Nexus, Intergalactic Museum of History
- Tools of Destruction
- Secret Agent Clank, In pursuit of Kingpin mission description.