Art imitated both life and death this Tuesday when Dethklok, the animated superstars of the Adult Swim series “”Metalocalypse,”” unleashed a brutal hour of melodic death metal upon a packed and writhing audience at Tempe’s Marquee Theatre.

Sponsored by Cartoon Network’s depraved younger brother Adult Swim, the tour has been billed as a 40-city death metal extravaganza co-headlined by Dethklok and Atlanta, Ga., metalheads Mastodon. Both bands having launched new albums this year — Dethklok’s chart-topping Dethalbum II in late September and Mastodon’s Crack the Skye in March — the tour registered among New Wave Metalomaniacs as both highly anticipated and unprecedented.

Why unprecedented? It’s worth mentioning that Dethklok started as a fake or “”comedy metal”” band in the vein of Spinal Tap and GWAR, but what really sets it apart from its visceral contemporaries is the fact that its members are cartoons. The music may be real — composed by “”Metalocalypse”” and “”Home Movies”” creator/voice-actor Brendon Small along with the drumming expertise of Gene “”the Atomic Clock”” Hoglan whose prior employment includes the bands Testament and Strapping Young Lad — but the band itself is a compilation of parodies and caricatures of the most archetypal personalities in metal lore. Lyricist Nathan Explosion, for example, is based on Cannibal Corpse front man George “”Corpsegrinder”” Fisher, and bassist William Murderface is a grim facsimile of Sabbath’s Geezer Butler.

Despite this, the band’s Dethalbum premiered at No. 21 on Billboard’s top 200 list, marking it the highest rated death metal album of all time before it was usurped this year by Dethalbum II, which topped out at No. 15. For a band that is technically fictional yet astronomically successful to be touring with the brutally avant-garde Mastodon is both an enigma and a modern rocker’s fantasy made manifest.

After brief but blood-pumping sets from High on Fire and Converge, Mastodon dominated the stage and played through the entirety of “”Crack the Skye”” with all the lumbering fury of their elephantine namesake. While singer/guitarist Brent Hinds prowled around Brann Dailor’s seismic drum set with the predatory gravitas of one of Tolkien’s orcs, Troy Sanders and Bill Kelliher united bellowing bass and shrieking guitar in a rocking, rollicking singularity.

In the background, a screen running the length of the stage displayed a montage of animated fractals and live-action recounts of tsarist Russia. The band retook the stage to play singles from their previous albums “”Blood Mountain”” and the “”Moby-Dick””-themed “”Leviathan”” over a sea of pumping fists in the crowd.

Dethklok, comprised of Small and Hoglan along with renowned rockers-for-hire Mike Keneally (lead guitar) and Bryan Beller (bass), was soon to follow, accompanied by the band’s fictional members on the screen behind them. With the same narrative aesthetic of the Adult Swim series, the set began with a meeting of “”The Tribunal,”” a secret sect of world leaders bent on preventing the hyper-violent Dethklok from attaining global power and ushering in the Metalocalypse.

Small and his comrades then launched into the Dethklok theme song before playing incendiary hit after hit from both of the band’s albums, the fictional Dethklok all the while testing the limits of homicide in brutal, bloodthirsty music videos onscreen behind them. A wild mosh pit erupted during “”Birthday Dethday,”” and pale reflections of the animated Dethklok fans being scalded to death during the “”Duncan Hills Coffee Jingle”” video ricocheted through the crowd, let loose their grungy locks and threw up The Horns to show solidarity with their fictional counterparts.

The accuracy of Small’s depiction of metal fans compared to the actual attendants was uncanny, and the sheer zeal of the undulating audience in the face of a band that was barely real was an astonishing testament to the power of art and media in modern society. When the band closed with their signature hits “”Thunderhorse”” and “”Go Into the Water,”” chants of “”Die for Dethklok!”” filled the arena as the crowd heaved about itself in a sweaty, exuberant mass. Small closed with some candid impersonations of the characters he voices on the show before introducing the actual musicians who so thoroughly rocked the Marquee, giving the members of Dethklok, both real and fictional, the accolades they’ve earned.

While not, perhaps, the most brutal band on Earth — as “”Metalocalypse”” may claim — Dethklok is certainly one of the most interesting case studies in heavy metal history, and that’s got to be worth something. Real or fictional, metal is metal, and that’s all anyone really needs.