EXO CBX

2016–present: Formation and debut with Hey Mama!

On July 29, 2016, Chen, Baekhyun and Xiumin appeared in a video titled "Reservoir Idols" during Exo's concert tour Exo Planet 3 – The Exo'rdium. They then released an original soundtrack titled "For You" for the SBS television drama series Moon Lovers: Scarlet Heart Ryeo on August 23, 2016. As a result, it was speculated that they would form EXO's first sub-unit. This was confirmed by S.M. Entertainment on October 5. On October 23, they performed "For You" for the first time as a unit at the 2016 Busan One Asia Festival. On October 24, the unit's name was announced to be EXO-CBX (shortened from ChenBaekXi), after the first letter of the members' stage names.

On October 31, EXO-CBX released their debut extended play Hey Mama!, which contains five tracks with a variety of genres including electronic dance, R&B ballad and retro pop, along with the music video for the title track. The group made their debut performance on M Countdown on November 3. On November 6, the "Reservoir Idols" video was officially released as a music video for "The One", one of the tracks from the album. Hey Mama! topped the Billboard World Albums chart and South Korean's Gaon album chart. On November 15, the group won their first music program trophy on The Show with "Hey Mama!". Later in November, EXO-CBX recorded a remake of the original soundtrack "Crush U" for the game Blade & Soul. They performed the song on November 18 at the N-Pop Showcase concert, part of the 2016 Blade & Soul world championship tournament. On December 25, "Crush U" music video was released.