Mutilator Defeated at Last is the sixteenth studio album by the American psychedelic rock band Thee Oh Sees, released on May 18, 2015, on Castle Face Records.

[1] In February 2016, the band released two unreleased tracks from the album's recording sessions, "Fortress" and "Man in a Suitcase".

[3] In a positive review, AllMusic's Tim Sendra praised core member John Dwyer's songwriting and the album's overall aesthetic, writing: "Dwyer continues to crank out consistently great to amazing songs and albums that overflow with hot-wired guitars, over-revved vocals, and giant, jagged hooks.

"[4] In another positive review Pitchfork's Aaron Leitko wrote: "As with Drop, this extra polish and attention benefits Mutilator.

"[10] NME's Cian Traynor praised the contributions of new members Tim Hellman and Nick Murray, writing: "The new rhythm section of Tim Hellman and Nick Murray slot seamlessly into place, helping bandleader John Dwyer capture a sound that epitomises Thee Oh Sees: tight but unhinged, urgent but infectious.