Meltan is a small Pokémon with a silvery body of liquid metal. Its head is hard and resembles a golden hexagonal nut, with a small black sphere floating inside. This sphere serves as its eye. It has a red tail that resembles an electrical wire with two tiny protrusions at the end. According to official concept arts, Meltan's liquid body is made of gallium, and it can cry gallium tears.
Meltan's body can corrode metal, which it then absorbs. It can generate electricity using the metal it absorbs, and then fire it from its eye. According to Professor Willow, Meltan has been described in ancient texts found in the same place as the Mystery Box, a mysterious item that attracts Meltan to its location when opened. Professor Willow also states that Meltan is said to be created from small shards when a Melmetal rusts and splits apart. Meltan is known to live in groups, until the day comes where one strong Meltan absorbs the group to evolve into Melmetal.
Meltan is the only Pokémon that can't have an origin mark from the core series. It can only legitimately have the Pokémon GO origin mark, as it has never been made available through gameplay or events of a core series game.
Meltan and its evolved form have several unique attributes:
They are the only Pokémon in Pokémon: Let's Go, Pikachu! and Let's Go, Eevee! whose Kanto Pokédex number (152) is not the same as its National Pokédex number (808). While KantoPokédex numbers are normally used throughout the game, the judge screen displays National Pokédex numbers, which is evident for Meltan and Melmetal.
They are the only Pokémon officially introduced in Generation VII that are not in the Alola Pokédex.
They are the only Pokémon obtainable in Pokémon: Let's Go, Pikachu! and Let's Go, Eevee! that cannot have the Let's Go origin mark.
They are the only Pokémon in the National Pokédex of Pokémon GO and Pokémon HOME (Switch only) to not be listed in a region section. Instead, they are put into "Unknown" and "Unknown Origins" respectively.
In the anime, Professor Oak is the person who gives Meltan its species name.
If Phione is not considered a Mythical Pokémon, Meltan and its evolution are the only Mythical Pokémon which did not debut in a movie.
Meltan may be based on a hexagonal nut, and its tail resembles an exposed wire. Its lower body is based on gallium, a metallic element with a relatively low melting point of about 86 °F (30 °C). Gallium is used to make semiconductors, and can easily "attack" other metals, such as aluminium and tin, to form alloys that are either very brittle or liquid at room temperature. These may be referenced with Meltan's liquid body, electric affinity, and ability to absorb metals.
Meltan may also be inspired by mercury, a metallic element that is liquid at room temperature. Much like gallium, mercury can also conduct electricity, as well as react with many other metals to form alloys known as amalgams.
Meltan may be a combination of melt, metal, and たん -tan (diminutive Japanese suffix). It may also be derived from molten.