is the debut extended play by Exo-CBX, the first official sub-unit of the South Korean-Chinese boy group Exo.

[1][2] On October 24, 2016, SM Entertainment announced that Chen, Baekhyun and Xiumin would debut as Exo's first official sub-unit Exo-CBX with an extended play titled Hey Mama!.

[3] On October 25, a teaser for the music video of the title track "Hey Mama!"

[4] On October 27, a highlight medley, featuring previews of the album's tracks, premiered on Apple Music's Beats 1.

On November 7, 2016, SM Entertainment released the music video for the second single "The One" in their official YouTube account.

was held at 8PM (KST) on October 31 on a special stage located at the east side of Samseong-dong COEX in Seoul.