Petter Karlsson
 Petter Karlsson (born May 31 1977) is a multi instrumentalist and singer of Holocoaster and was a member of Swedish symphonic metal band Therion (2004–2008) lead vocalist and guitarist of Argento member of other several bands: Master Massive Kajarr Conspiracy.He had a big impact on Therion's 13:th album Gothic Kabbalah and was involved in the writing of 9 of the 15 songs.In the year 2009 he started the band Holocoaster.