He also worked with underground emcee/Record producer Necro for his album entitled "Death Rap". Ellefson is also a member of a cover band called Hail!. Ellefson, DeGrasso (Mike Portnoy for 2010), Tim "Ripper" Owens and Andreas Kisser formed the band in late 2008. The band was, as of April 2009, touring Europe. Ellefson participated in the Christmas Rock project Northern Light Orchestra, he performed bass on many of the 17 tracks produced by rock drummer Ken Mary and also at the live show Christmas in April Orpheum Theatre, Phoenix, Arizona. On February 8, 2010, Ellefson received a text message from Megadeth drummer Shawn Drover, saying "if ever there was a time for you and Dave [Mustaine] to talk, now is it". Ellefson was invited to rehearse with the band. After the phone call, the news was released that Ellefson would return to the Megadeth lineup. Ellefson was quoted saying "it felt like I never left" after their first rehearsal together. In 2013, Ellefson announced that his autobiography, entitled "My Life With Deth", would be issued by American publisher Howard Books. The memoir was co-written with author Joel McIver, and features a foreword by Alice Cooper. In 2018, it was announced that Ellefson had begun work on "More Life With Deth", the follow-up to his 2013 memoir "My Life With Deth", to be co-written with Ellefson's business partner, and frequent collaborator, Thom Hazaert. The book was released on July 16, 2019, by UK based Jawbone Press, and features contributions from Alice Cooper, K.K. Downing of Judas Priest, Dan Donegan of Disturbed, Brian Welch of Korn, Mark Slaughter, Ron Keel, Jason McMaster of Dangerous Toys, Frank Bello of Anthrax, Chris Adler (Lamb of God, ex-Megadeth), Mark Tremonti of Creed and Alter Bridge, Kiko Loureiro and Dirk Verbeuren of Megadeth, actor Kristian Nairn ("Game of Thrones"), and more, plus a foreword by "My Life With Deth" co-author, and "Bass Player Magazine" editor Joel McIver. In October 2015 it was announced that Ellefson had launched a record label and production company, Ellefson Music Productions, also known as EMP Label Group, and would release "In Your Face", the debut EP from Phoenix-based all-girl pop-punk group Doll Skin (which Ellefson also produced), in conjunction with Megaforce Records in North America, and Cargo Records in Europe.