The band originated in 2005 from a song titled "The Kids" that Jorel Decker (J-Dog) and Aron Erlichman (Deuce) posted on the band's MySpace profile to positive reviews, leading them to form the group Hollywood Undead with their friends "Shady" Jeff Philips, George Ragan (Johnny 3 Tears), Jordon Terrell (Charlie Scene), Dylan Alvarez (Funny Man), and Matthew St. Claire (Da Kurlzz). In an interview with Shave magazine, J-Dog explained that when forming the band "Whoever was in the room at the time and played an instrument was in the band." Shady Jeff later left the group reasons currently unknown to the public. He currently works as a mechanic and is working on converting diesel cars into vehicles that can run on vegetable oil.[3]
The band only took one year working on their debut album, Swan Songs. The other two years were spent looking for a company that wouldn't try to censor the album. They first signed a record contract with MySpace Records in 2005 but they left the label after the label tried to censor their first album. They then signed a contract with A&M/Octone Records and their first album, Swan Songs was released on September 2, 2008 and reached No.22 on the Billboard 200 in its first week of release, selling 21,000 copies which was later on released in the United Kingdom on May 18, 2009 with two bonus tracks. On June 23, 2009, Hollywood Undead released Swan Songs B-Sides EP through iTunes.
The band released a CD/DVD set entitled Desperate Measures on November 10, 2009. The set includes a CD of previously unreleased six new songs, three of which are cover songs, as well a previously unreleased remix of "Everywhere I Go", and six live recordings of songs from Swan Songs, and a DVD of a full live performance by the band.In December 2009, the band won Best Crunk/Rock Rap Artist at the Rock on Request Awards..