Metalis is a planet in the Solana Galaxy featured in Size Matters. It is a junkyard planet filled with abandoned robots and scrap, with fleets of ships dumping waste onto the planet, and is seemingly otherwise uninhabited. Old robots abandoned on this planet complete in the Robot Wars, a destruction derby in which robots fight one another in armed vehicles, and take part in sports. This operates in the planet's Junkyard LXIV. It was here that Clank was dumped on the planet by the technomites.
At some point, Metalis became the dumping ground for garbage and scrap metal. After finding Luna on Kalidon, Clank was zapped and dumped on the planet. In "Survive Robot War III", Clank immediately awoke on the planet in the middle of the destruction derby, and had to compete in the tournament to survive.
After surviving, Skrunch landed on the planet and showed Clank information about Captain Qwark's real parents, as well as footage of Ratchet on Medical Outpost Omega. Following this, in "Escape the planet", Clank found an Ultra-Mech Pad and transformed into Giant Clank in order to fly to the space station and help Ratchet.
Metalis has a brown and likely polluted sky. Its surface is entirely covered in heaps of scrap metal around water, which reflects the brown sky. Several starships can be seen dumping more scrap onto the planet's piles, and the planet appears uninhabited with no signs of organic life. In addition to piles of scrap metal are the remains of crashed starships likely abandoned on the planet, and tall towers.
Junkyard LXIV's arena in which the Robot Wars takes place is located in the remains of a dome-shaped structure, though its roof is destroyed, leaving little behind. The arena is located in the center of a pit of water, with an empty audience podium surrounding it. As the arena contains several working hazards that change between matches, it is likely the remains of a gladiatorial combat arena which was dumped on the world.
Nearby the arena is a crane that connects to a small patch of metal that provides traversable ground. Here, a landing pad is located, a tunnel blocked off until opened with the Polarizer, as well as an abandoned Ultra-Mech Pad. Surrounding it are more piles of scrap and starship debris out in the water, with a tower in the distance. The blocked off tunnel leads to a long path containing multiple conveyor belts, trash crushers, machinery emitting jets of flame, as well as groups of guard torsos. At the end is a large platform called the arena, although the only thing found there is a titanium bolt and a large circle of bolt crates.