Big Iron refers to a song from the album of Marty Robbins, titled Gunfighter Ballads and Trail Songs.
The song became popular online, after being included in Fallout: New Vegas, spawning parodies and remixes.
Marty Robbins’ Gunfighter Ballads and Trail Songs album was released as an LP in 1959 by Columbia Records.
The album gained prominence online following the release of Obsidian Entertainment’s Fallout: New Vegas in 2010, as the song “Big Iron” was included in the game’s soundtrack.
During the 2010’s, the song’s popularity remained true, as users would upload parodies, featuring the song to YouTube.
The lyrics of “Big Iron” were also featured in memes as copypasta.