Meltan

Meltan is a small Pokémon with a shiny, silvery body made of liquid metal. Its head is a golden hexagon with a large circular hole in its center, resembling a hexagonal nut. Floating inside the hole is its eye. A red tail extends from its body with two tiny protrusions at the end.

It is a curious and expressive Pokémon. Meltan's liquid arms and legs can corrode and absorb metal into its body, which it uses to generate electricity. Its eye can use this energy to fire an attack against opponents.[1]Meltan are instinctively drawn towards each in order to combine into Melmetal.

Many Ditto transformed into Meltan have been observed in Pokémon GO, including in Professor Willow's field work. It has also 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. As seen in the anime, Meltan can travel underwater.