Kerwan

Kerwan was a bustling planet that was home to the gigantic city of Metropolis. In Deadlocked, Sasha became the Mayor of Metropolis.

In Ratchet & Clank, Ratchet and Clank acquired an Infobot on planet Novalis that featured Captain Qwark at Big Al's Roboshack. They tried to find the hero in green, but ultimately only left the planet with a newly-fitted Helipack, a Swingshot, and an Infobot to planet Eudora.

In Up Your Arsenal, Ratchet and Clank faced Dr. Nefarious's Biobliterator menace and had to defeat Klunk.

In Tools of Destruction, the duo had to fought off Emperor Percival Tachyon's deadly space armada. According to IRIS Tachyon and his army had left Kerwan after combing Metropolis for the Lombax Secret and the city was under reconstruction. Although this was the same Metropolis from the first and third game it looked completely different in Tools of Destruction mainly because of high definition. This made the city look much more realistic, and alive with sky traffic everywhere, Ratchet also explored a part of the gigantic city never before seen, and this new area had railway tracks that were not seen before either and had Ratchet grinding on them and dodging speeding Mag Trains.

Changes in appearance
Although Kerwan was the same planet in all three of its appearances, it had undergone possibly the most drastic terrain changes ever seen in the Ratchet & Clank series. During Ratchet's first visit, Kerwan strongly resembled Coruscant from Star Wars, with a surface that took on the appearance of a worldwide city. When Ratchet later returned, Kerwan was depicted as a lush, vegetated world covered in vast oceans. As the duo took off for Polaris it looked like a red deserty world even though Kerwan was not a desert world although it could have a few, it may had other terrain as well, like Coruscant from Star Wars, has mountains. In a commercial later viewed, Kerwan looked lush and vegetated again. Kerwan is seemed to be a gas giant like Jupiter.

Characters on Kerwan

 * Big Al
 * Helga
 * Qwark Bot
 * Dr. Nefarious
 * Lawrence
 * Klunk
 * Galactic Rangers
 * Emperor Percival Tachyon

Non-Native

 * Blarg Commanders
 * Robodogs
 * Mine Layers
 * Blarg Helicopter Commander
 * Blarg Generators
 * One-Eyed Tyhrranoid v2s
 * One-Eyed Robonoids
 * Three-Eyed Tyhrranoid v2s
 * Three-Eyed Robonoids
 * Tyhrranoid Commanders
 * Robonoid Commanders
 * Tank Bots
 * Giant Klunk
 * Ultra Mecha-Tyhrranoid
 * Tyhrranoid Missile Stations
 * Insectoids
 * Insectoid Swarms
 * Dr. Nefarious
 * Drophyd Sentry
 * Drophyd Trooper
 * Tesladrone
 * Tachyon Gunship
 * Tachyon Warship
 * Tachyon Walker

Trivia

 * If you look closely, the landmass in the western hemisphere resembles our real-life North and South Americas.
 * Apparently, the Ratchet & Clank instruction manual mentions there is only one pet shop in Kerwan (possibly in Metropolis), and it specialises in the Hatcher Lizard.
 * While riding on the Grind-Rails in Ratchet & Clank Future: Tools of Destruction, a silver model of the planet is shown, probably representing the Planetary Defense Center. It shows the continents, and where they were placed, of Kerwan. (In Ratchet & Clank: Up Your Arsenal, it looked like Todano, except with mirrored continents).
 * At the back of the box for Ratchet & Clank, there was a Wanted Poster. It had a Last Seen category, and said "Planet Metropolis" rather than planet Kerwan.

Appearances

 * Ratchet & Clank
 * Ratchet & Clank: Up Your Arsenal
 * Ratchet: Deadlocked (cameo)
 * Ratchet & Clank Future: Tools of Destruction