Monsta is a name of at least four artists:
[1] A trio of Bryn Christopher, Rufio Sandilands & Rocky Morris. Their first official release was the Monsta EP (Oct 2012, Owsla - Skrillex's label). Their latest release is the Evolution EP, released on Polydor Records. The group also changed their name to I See MONSTAS prior to this release, due to a supposed copyright claim from another group.
Sites: Discogs
[2] A north west England punk rock / electroclash band, comprising: Laura Follin, Emma Stockton (aka Emma Divine) & James Wilson (aka Jim Wilson).
Sites: Discogs
[3] a gangsta rapper affiliated with The Regime whose debut album 'Pacific Coast Highway' came out in spring 2011.
[4] A dubstep producer, artist and runs the Monsta Dubs record label.