Bastard!!: Heavy Metal, Dark Fantasy (BASTARD!!-暗黒の破壊神- Basutādo!! Ankoku no Hakaishin?, lit. "Bastard!! The Destructive God of Darkness") is a manga by Kazushi Hagiwara. It first appeared in Weekly Shōnen Jump, in 1988, and continues to be published irregularly today in Ultra Jump. Currently, it spans 27 volumes.
Kazushi Hagiwara is an enthusiastic fan of heavy metal music and Dungeons & Dragons, using ideas from both of these in the Bastard!! story. Many characters and places in the story, for instance, are named after members of Hagiwara's favorite bands. Hagiwara also attributes the manga Devilman by Go Nagai as a primary influence on his artwork.