Question: Who is the American bass guitarist known for his work in a virtual death metal band featured in "Metalocalypse"?

Context paragraphs:
Marcin Rygiel: Marcin "Martin" Rygiel, (born 30 April 1983 in Krosno, Poland), is a Polish musician, best known as the former bass guitarist of the technical death metal band Decapitated from 1997 to 2007, leaving several months before their hiatus.  He was also a member of the avant-garde metal/black metal band Lux Occulta from 1998 until their hiatus in 2002.  In June 2008, Rygiel toured with the death metal band Vader as a session musician.  In 2010, Rygiel joined California-based death metal band Annihilated as their bassist until 2013.  He was the bassist for the Egyptian-American death metal band Nader Sadek from 2014 to 2015.

Brendon Small's Galaktikon II: Become the Storm: Brendon Small's Galaktikon II: Become the Storm is the second solo album by Brendon Small, known for his work on the animated television shows "Metalocalypse" and "Home Movies", and as creator of virtual death metal band Dethklok.  The album was released on August 25, 2017 through Megaforce Records.  The album features Dethklok members Gene Hoglan and Bryan Beller, on drums and bass, respectively.  Since Brendon Small no longer holds the rights to the Dethklok name, Gene Hoglan has suggested that this album would serve as a "new Dethklok album".

Bryan Beller: Bryan Beller (born May 6, 1971) is an American bass guitarist known for his work with Joe Satriani, The Aristocrats, Dethklok, Mike Keneally, Steve Vai, James LaBrie of Dream Theater and Dweezil Zappa.  He has been Joe Satriani's tour bassist for both the "Unstoppable Momentum" (2013–14) and "Shockwave" (2015–16) world tours in addition to featuring on the "Shockwave Supernova" record.  Beller is also the bassist/manager of the rock/fusion super-trio The Aristocrats (with Guthrie Govan on guitar and Marco Minnemann on drums).  The Aristocrats have released three studio albums, along with two live releases documenting the band’s world tours in support of their debut album "The Aristocrats" and sophomore album "Culture Clash".  Their most recent studio album "Tres Caballeros" is the focus of their current world tour, which began in the summer of 2015 and will extend through to late 2016.

Metalocalypse (season 3): The third season of the animated show "Metalocalypse" originally aired on Adult Swim from November 8, 2009 to October 24, 2010 with 10 episodes.  The show follows virtual death metal band Dethklok.  This season featured a 22-minute runtime (30 with commercials).

Metalocalypse (season 2): The second season of the animated show "Metalocalypse" originally aired on Adult Swim from September 23, 2007 to September 7, 2008 with 19 episodes.  The show follows virtual death metal band Dethklok.  The majority of the music featured this season was released on the 2009 album "Dethalbum II".  The first episode of this season, "Dethecution" was released as part of the deluxe edition of "The Dethalbum".  This season featured the new re-recorded version of the "Deththeme", released as a hidden track on "The Dethalbum".

Metalocalypse (season 1): The first season of the animated show "Metalocalypse" originally aired on Adult Swim from August 6, 2006 to December 17, 2006 with 20 episodes.  The show follows virtual death metal band Dethklok.  The majority of the music featured this season was released on the 2007 album, "The Dethalbum".

Brendon Small: Brendon Small (born February 15, 1975) is an American voice actor, stand-up comedian, producer, writer, animator and musician.  He is best known as the co-creator of the animated series "Home Movies" (along with Loren Bouchard) and "Metalocalypse" (along with Tommy Blacha) and as the creator of the virtual death metal band Dethklok.

Brendon Small's Galaktikon: Brendon Small's Galaktikon is the solo album debut by Brendon Small, known for his work on the animated television shows "Metalocalypse" and "Home Movies", and as creator of virtual death metal band, Dethklok.  The album features Dethklok members Gene Hoglan and Bryan Beller, on drums and bass, respectively.  Small described the album as a "high-stakes, intergalactic, extreme rock album" and describes it as being similar to Dethklok but with more rock elements and melodic vocals.  Like on previous Dethklok albums, Ulrich Wild produced the album and Antonio Canobbio designed the cover art.  The album's release coincided with the premiere of the fourth season of "Metalocalypse".  The album was also released on vinyl in late June 2012.

Dethalbum III: Dethalbum III is the third full-length album by virtual death metal band Dethklok, from the Adult Swim animated series "Metalocalypse".  The CD and deluxe CD/DVD were released on October 16, 2012.  It contains music from the second, third and fourth seasons of the show.  Like "The Dethalbum" and "Dethalbum II" before it, the music is performed by the show's creator Brendon Small and drummer Gene Hoglan.  Additionally, the band's live bassist, Bryan Beller, performs on the album.

Dethklok: Dethklok is a virtual death metal band featured in the Adult Swim animated television series "Metalocalypse".

Supporting paragraphs: Bryan Beller Dethklok
Answer: Bryan Beller