Recorded after the departure of bass player Kevin Rutmanis, the songs on Anonymous are based on Native American compositions researched by guitarist Duane Denison.

Anonymous was recorded after the departure of Tomahawk's bass player Kevin Rutmanis, leaving a lineup composed of Mike Patton, Duane Denison and John Stanier.

[2] The songs on Anonymous are based on Native American compositions, which Denison had researched while touring Indian reservations with musician Hank Williams III.

[4] Denison found transcriptions of traditional music, and based his work for the album on these—the title Anonymous is a reference to the uncredited composers of this source material.

[1] Lymangrover compared the album to Frank Zappa's Apostrophe (') and Mr. Bungle's California, also noting similarities to Patton's other supergroup Fantômas.

[7] The review praised Denison's work on retaining a faithful Native American tone on the compositions, while still allowing the album to sound familiar as a Tomahawk recording.

[3] Crock felt that the group were respectfully faithful to the musical culture within which they were working, but described the resultant sound as resembling a film score more than a live band.