Self - Narrator (294 episodes, 2003-2018)
Self - Host (284 episodes, 2003-2018)
Self - Host / Self - Builder / Self / Self - Body Mold Model (241 episodes, 2003-2018)
Self - Host / Self - Builder (241 episodes, 2004-2018)
Self - Host / Self - Builder (216 episodes, 2005-2018)
Self - Builder / Self / Self - Guest Builder (30 episodes, 2004-2013)
Self - Folklorist (19 episodes, 2003-2004)
Self - Shop Assistant (19 episodes, 2004-2011)
Self / Self - Retired FBI Agent (15 episodes, 2005-2012)
Self - Host (13 episodes, 2017-2018)
Self - Mythdog (13 episodes, 2017-2018)
Self / Roaring Forties / Self - Alemeda County Sherrif's Office (11 episodes, 2007-2013)
Self (12 episodes, 2006-2010)
Self (8 episodes, 2005-2007)
Self - Host (9 episodes, 2009-2010)
Self / Self - Acoustician (4 episodes, 2003-2011)
Self - Amateur Rocket Expert / Self (6 episodes, 2003-2005)
Self - Intrepid Specialties / Self (3 episodes, 2013-2016)
Self / Self - New Mexico Tech / Self - Vice President for Research, NMT (3 episodes, 2008-2013)
Self (3 episodes, 2003-2006)
Self / Pyrotechnician (5 episodes, 2003-2005)
Self (3 episodes, 2004-2007)
Self / Self - Blueprint Artist (3 episodes, 2005-2012)
Self (3 episodes, 2005-2008)
Self (3 episodes, 2006-2008)
Self / Self - Author, 'The Oxford Companion to Wine' / Self - Manager, The Bone Room (2 episodes, 2006-2007)
Self (3 episodes, 2006)
Self (3 episodes, 2008-2009)
Self - Guest Host (2 episodes, 2018)
Self - Living Legend / Self - Special Guest (2 episodes, 2013-2015)
Self - Orthopaedic Surgeon / Self - Orthopedic Surgeon (2 episodes, 2012-2013)
Self - Law Enforcement Pursuit & Evasion Driving Instructor (2 episodes, 2018)
Self (2 episodes, 2012-2016)
Self - Former AMA Supercross Rider (2 episodes, 2013-2017)
Self - Professional Stuntman / Self - stuntman (2 episodes, 2009-2012)
Self (2 episodes, 2003-2006)
Self (3 episodes, 2003-2004)
Self (2 episodes, 2004-2007)
Self (2 episodes, 2004-2005)
Self (2 episodes, 2005-2008)
Self (2 episodes, 2005-2007)
Self (2 episodes, 2005-2006)
Self / Self - NASA (2 episodes, 2006-2012)
Self (2 episodes, 2006)
Self - Scent expert (1 episode, 2007-2010)
Self (2 episodes, 2007)
Self (1 episode, 2010-2016)
Self - Olympic Runner (2 episodes, 2011-2013)
Self - High Speed Camera Operator / Self - Speciality Camera Operator (2 episodes, 2012-2015)
Self / Volunteer (2 episodes, 2012-2013)
Zombie (1 episode, 2013-2016)
Self - Executive Producer & Showrunner, The Simpsons, 8 Emmys & 1 Peabody Award (1 episode, 2015)
Mike Ehrmantraut (1 episode, 2015)
Self - Whip Master and Weapons Expert (1 episode, 2015)
Self - Sword Master (1 episode, 2015)
Self - id Software (1 episode, 2015)
Self - Driving Instructor (1 episode, 2015)
Self - Director: Pebble Beach Golf Academy (1 episode, 2015)
Self - Formula Drift Racer, Team - Conrad Grunewald Racing (1 episode, 2015)
Self - Motion Picture Armorer (1 episode, 2015)
Self - Electronics Expert (1 episode, 2016)
Self - Universal Hovercraft (1 episode, 2016)
Self - Owner: Third Street Boxing Gym (1 episode, 2016)
Self - Doom Avatar (1 episode, 2015)
Self - The Invigilator (1 episode, 2015)
Self - Professional Competitive Shooter (1 episode, 2015)
Self - High Speed Camera Operator (1 episode, 2015)
Self - Merrick Cheney Design, Richmond, CA (1 episode, 2015)
Self - Reverse Driving Master (1 episode, 2015)
Self - Medieval Weapons Expert (1 episode, 2017)
Self - Air Technology Laboratories (1 episode, 2017)
Self - X-Ray Expert (1 episode, 2017)
Self - Applied Neuroscientist (1 episode, 2017)
Self - Stunt Rigger (1 episode, 2018)
Self - Master Gun Fighter (1 episode, 2018)
Self - Show Dog Judge (1 episode, 2018)
Self - Champion Archer & Instructor (1 episode, 2018)
Self - Storm Chaser (1 episode, 2010)
Self - Guest Star (1 episode, 2013)
Self - Captain: Time Bandit (1 episode, 2013)
Self (1 episode, 2013)
Self - Quake Expert (1 episode, 2013)
Self - Princess Leia (1 episode, 2014)
Self - Hot Saw Legend (1 episode, 2017)
Self - Technician: Minixray Inc. (1 episode, 2017)
Self - Beauty Pageant Judge (1 episode, 2018)
Self - Explosives Expert (1 episode, 2018)
Self (1 episode, 2010)
Self - Sound Designer (1 episode, 2011)
Self - Ordinance Tech, NMT (1 episode, 2011)
Self - Culinary Mastermind (1 episode, 2012)
Self (1 episode, 2012)
Self - Forensic Pathologist (1 episode, 2012)
Self - Impalement Artist (1 episode, 2012)
Self - Professor of Meteorology, SFSU (1 episode, 2012)
Self - Special Guest (1 episode, 2013)
Self - Captain: Seabrooke (1 episode, 2013)
Self - Highly Trained Defecator (1 episode, 2013)
Self - Professional Stunt Driver (1 episode, 2014)
Self - Owner: Herding 4 Ewe (1 episode, 2014)
Self - Matter Distiller: St. George Spirits (1 episode, 2014)
Self - Tennis Pro (1 episode, 2014)
Self - Neon Expert (1 episode, 2014)
Self (1 episode, 2016)
Self - Orthopaedic Trauma (1 episode, 2017)
Self - Forensic Sketch Artist (1 episode, 2018)
Self - Shooting Incident Analyst (1 episode, 2011)
NMT / Self - Research Engineer, EMRTC (1 episode, 2011)
Self - Owner, East Bay Vivarium & Snake Handler (1 episode, 2011)
Self - Geologist (1 episode, 2012)
Self - Dir. Sports Nutrition, UC Davis (1 episode, 2012)
Self - Navigation Expert: CMA (1 episode, 2013)
Self - Using Toilets Since 1992 (1 episode, 2013)
Self - Field Operation Manager: US Geological Survey (1 episode, 2013)
Roaring Forties (1 episode, 2013)
Self (1 episode, 2003)
Self (2 episodes, 2003-2004)
Narrator (UK) (1 episode, 2003)
Self (2 episodes, 2003-2005)
Self (1 episode, 2004)
Self (1 episode, 2005)
Self (1 episode, 2006)
Self - Scientist (1 episode, 2006)
Self (1 episode, 2007)
Self - Golden Gate Western Wear (1 episode, 2007)
Self - Senior Instructor Bujinkan SF Dojo (2 episodes, 2007)
Baseball Catcher (1 episode, 2007)
Field Producer (1 episode, 2007)
Self - Museum Curator (1 episode, 2007)
Self - Guard dog (1 episode, 2007)
Self - Mechanic (1 episode, 2007)
Self (1 episode, 2008)
Self - Supersonic Pilot (1 episode, 2009)
Self - Production Assistant (1 episode, 2009)
Self - Alameda County Sheriffs Department (1 episode, 2009)
Self - Swimmer (1 episode, 2009)
Self - Professor of Epidemiology, UC Berkeley (1 episode, 2009)
Self - Design Engineer, Aerojet (1 episode, 2009)
Self - Polysomnologist (1 episode, 2009)
Self - Diving Expert, Dive Lab (1 episode, 2009)
Self (1 episode, 2009)
Self - Explosives Research Engineer, New Mexico Tech (1 episode, 2009)
Self - Professor of Neurology, University of California (1 episode, 2009)
Self - National Instruments (1 episode, 2009)
Self - Tandem Hangliding Instructor, Skypuppy Hang Gliding (1 episode, 2009)
Self - Microbiology Expert (1 episode, 2009)
Self - Operations Manager, Waste Management (1 episode, 2009)
Self - Fashion Consultant (1 episode, 2009)
Self - Tandem Hangliding Instructor, Bay Area Hangliding (1 episode, 2009)
Self - GM, California Center for Sleep Disorders (1 episode, 2009)
Self - Stanford University (1 episode, 2009)
Volunteer Guinea Pig (1 episode, 2010)
Self (1 episode, 2011)
Acrobat / Self - Gymnast (1 episode, 2011)
Volunteer (1 episode, 2012)
Self - Sound Recordist (1 episode, 2012)
Self - Explosives Technician (1 episode, 2012)
Pirate (1 episode, 2012)
Self - Firearms Consultant (1 episode, 2012)
Self - Odor Scientist, Monell Chemical Senses Center (1 episode, 2012)
Self - Main Unit Cameraman (1 episode, 2012)
Self - Indycar Driver (1 episode, 2013)
Extra (1 episode, 2013)
Zombie (1 episode, 2013)
Self (1 episode, 2015)
Self - Commander, 9th Reconnaissance Wing, Beale Air Force Base (1 episode, 2015)
Self - Crane Operator, Doc Bailey Construction Equipment (1 episode, 2015)
Zombie (1 episode, 2016)
Zombie Volunteer (1 episode, 2016)
Red Shirt Zombie (1 episode, 2016)
Self - Driver (1 episode, 2017)
Self (1 episode, 2018)
Self -Jackson's owner (1 episode, 2018)
Self - Bruno's Owner (1 episode, 2018)
Self - Dog Owner (1 episode, 2018)
Volunteer Guinea Pig (uncredited) (2 episodes, 2010)
Zombie (uncredited) (2 episodes, 2013-2016)
Self (uncredited) (1 episode, 2008)
Volunteer Guinea Pig (uncredited) (1 episode, 2010)
Zombie (uncredited) (1 episode, 2013)
Smart Zombie (uncredited) (1 episode, 2013)
Broken Glass Zombie (uncredited) (1 episode, 2013)
Stormtrooper (uncredited) (1 episode, 2014)
Self (uncredited) (1 episode, 2016)
Zombie (uncredited) (1 episode, 2016)
Shopping Volunteer (uncredited) (1 episode, 2016)
Volunteer (uncredited) (1 episode, 2016)
Backpack Zombie (uncredited) (1 episode, 2016)
Office Zombie (uncredited) (1 episode, 2016)