Meltan has a small, silvery body of liquid metal with a golden hexagonal nut for a head housing a floating black sphere as its eye, and a red wire-like tail; its arms can stretch longer or shorter. Its liquid body is made of gallium, letting it corrode and absorb metal, which it circulates internally to generate electricity. Meltan can only evolve into Melmetal in Pokémon GO, making it the only Mythical Pokémon capable of evolution and the only evolving Pokémon that cannot be evolved in the core series, so it is unaffected by Eviolite and can be caught in Poké Balls its evolved form cannot.
Meltan is the only Pokémon with the Magnet Pull ability that cannot also have Sturdy. Meltan and Melmetal are also the only Pokémon in Let's Go, Pikachu! and Let's Go, Eevee! not introduced in Generation I, the only Pokémon introduced in Generation VII absent from the Alola Pokédex, and the only ones whose Kanto Pokédex number does not match their National Pokédex number.
Meltan has an SM Black Star promo illustrated by Shin Nagasawa, and Unbroken Bonds gave it a Common by Kouki Saitou. Darkness Ablaze, Fusion Strike, and a dedicated Pokémon GO set each added a Common, and the Scarlet & Violet era carried it through Obsidian Flames, a Temporal Forces pair including an Illustration rare by Masa, and a Stellar Crown pair of Commons.
Unbroken Bonds' Common Meltan illustrated by Kouki Saitou, its earliest non promo printing.
Pokémon GO's Common Meltan illustrated by Sumiyoshi Kizuki, from the set built around that game.
Temporal Forces' Illustration rare Meltan illustrated by Masa.
Stellar Crown's Common Meltan illustrated by Yuka Morii.
Only in Pokémon GO, into Melmetal; it cannot evolve in the core series games.
A liquid gallium body, according to official concept art, letting it corrode and absorb metal for energy.
Our catalog lists 10 Meltan cards across 8 sets.

メルタン
Steel
Meltan is the Hex Nut Pokémon, a Mythical Steel type made of liquid gallium that can only evolve into Melmetal within Pokémon GO, never in the core series games. Our catalog lists 10 Meltan cards across 8 sets, from an SM Black Star promo through Stellar Crown's paired commons.
No published index yet — too few of Meltan’s cards trade often enough to strike one.