Description from original post (created 2015-11-01 00:19):
Registeel's body is not only scratchable, sturdier than any type of metal (The cause being tempered by underground pressure), shrinkable and flexible, but studies have also found out that said body is apparently hollow. People in the ancient times have imprisoned Registeel underground for several years. The diet of this Pokémon is not known at this time. Rumors have it that the metal consisting this Pokémon is of a different substance from another world.~Registeel's Pokédex entries combined into one
The shiny form can be found here. Also, the female version can be found here.