Leviathan is the second album by American metal band Mastodon, released in 2004 by Relapse Records. The album is the group's first concept album and is loosely based on the Herman Melville novel Moby-Dick, and the songs "Iron Tusk", "Blood and Thunder", "I Am Ahab" and "Seabeast" were released as singles. Three magazines awarded it Album of the Year in 2004: Revolver, Kerrang! And Terrorizer. In 2009 MetalSucks named Leviathan the best metal album of the 21st century. Leviathan was also released with an audio DVD OF DVD-Video format in a limited edition set with a black and gold slipcase. The album brought Mastodon great critical acclaim and, thanks to the ensuing tour, a considerably larger fan base. Leviathan had sold 103,000 copies by September, 2006. Guitarist Bill Kelliher considers this album to represent the water element, in keeping with elemental tetra logy of concept albums.