I. Introduction
Red Velvet's first sub-unit released its first extended play (EP), Monster, on July 6, 2020. The EP had two singles, lead track "Monster" and "Naughty."
II. Background & Release
The sub-unit was announced in April 2020 with a release in June. However, it was delayed until July. The EP featured 6 songs with a combination of dubstep, future house, dance pop, K-pop and R&B. The physical release had three different versions: Top Note, Middle Note, Base Note. The single "Naughty" is in the physical release but was released separately in digital.
III. Tracklist
| Title | Lyrics | Music | Arrangement | Length |
| "Monster" | Kenzie | Yaakov "Yash" Gruzman, Delaney Jane, Jenson David, Aubrey Vaughan, Yoo Young-jin | Yaakov "Yash" Gruzman, Yoo Young-jin | 2:58 |
| "Naughty" | JQ (Makeumine Works), Lee Yeon-ji (Makeumine Works) | Jonatan Gusmark (Moonshine), Moonshine Ludvig Evers (Moonshine), Louise Frick Seven, Charite Viken Reinas, Yoo Young-jin | Moonshine, Yoo Young-jin | 3:18 |
| "Diamond" | KIm Yeon-seo (ADC Music) | Daniel "Obi" Klein, Kim Yeon-seo (ADC Music), Andreas Oberg | Daniel "Obi" Klein | 3:16 |
| "Feel Good" | Lee Seu-ran | Jonatan Gusmark (Moonshine), Moonshine Ludvig Evers (Moonshine), Tania Doko, Maribelle Anes | Moonshine | 3:13 |
| "Jelly" | Park Green (Joombas) | minGtion (ADC Music), Andrew ADC Music Choi (ADC Music), Kim Yeon-seo (ADC Music) | ADC Music | 3:12 |
| "Undercover" (Seulgi solo) | Kim Yeon-seo (ADC Music) | Joseph Hong, Shim Jae-won (BeatBurger), Kim Yeon-seo (ADC Music) | Joseph Hong | 3:41 |
IV. Spotify Playlist
V. Videos
Monster
Naughty
VI. Promotional Photos
VII. Reception
The EP reached #2 on the Korean Gaon Album charts, as well as debuting at #1 on the iTunes album charts for 52 countries. It also debuted at #5 on the U.S. Billboard World Albums Chart. The eponymous title track debuted at #8 on the Gaon Digital Chart and topped the Gaon Download Chart for a period in July. It also charted in the U.S. on the World Digital Song Sales Chart, peaking at #7, reached #2 on the K-pop Hot 100 chart and charted in Malaysia, Singapore and New Zealand. The second single, "Naughty" charted at #83 on the Gaon Download Chart and #99 on the K-pop Hot 100. In the U.S., it reached #6 on the World Digital Song Sales chart.
