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 - Motion Picture Armorer (1 episode, 2015)
Self - Formula Drift Racer, Team - Conrad Grunewald Racing (1 episode, 2015)
Self - Driving Instructor (1 episode, 2015)
Self - Director: Pebble Beach Golf Academy (1 episode, 2015)
Self - Universal Hovercraft (1 episode, 2016)
Self - Owner: Third Street Boxing Gym (1 episode, 2016)
Self - Electronics Expert (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 - Reverse Driving Master (1 episode, 2015)
Self - Merrick Cheney Design, Richmond, CA (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 - Champion Archer & Instructor (1 episode, 2018)
Self - Show Dog Judge (1 episode, 2018)
Self - Master Gun Fighter (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 - Technician: Minixray Inc. (1 episode, 2017)
Self - Hot Saw Legend (1 episode, 2017)
Self - Explosives Expert (1 episode, 2018)
Self - Beauty Pageant Judge (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 - Forensic Pathologist (1 episode, 2012)
Self - Professor of Meteorology, SFSU (1 episode, 2012)
Self - Impalement Artist (1 episode, 2012)
Self (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 - Neon Expert (1 episode, 2014)
Self - Tennis Pro (1 episode, 2014)
Self - Matter Distiller: St. George Spirits (1 episode, 2014)
Self - Owner: Herding 4 Ewe (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)
Self - Owner, East Bay Vivarium & Snake Handler (1 episode, 2011)
NMT / Self - Research Engineer, EMRTC (1 episode, 2011)
Self - Dir. Sports Nutrition, UC Davis (1 episode, 2012)
Self - Geologist (1 episode, 2012)
Self - Using Toilets Since 1992 (1 episode, 2013)
Self - Navigation Expert: CMA (1 episode, 2013)
Roaring Forties (1 episode, 2013)
Self - Field Operation Manager: US Geological Survey (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 - Senior Instructor Bujinkan SF Dojo (2 episodes, 2007)
Field Producer (1 episode, 2007)
Self - Golden Gate Western Wear (1 episode, 2007)
Self - Museum Curator (1 episode, 2007)
Self - Guard dog (1 episode, 2007)
Self - Mechanic (1 episode, 2007)
Baseball Catcher (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 (1 episode, 2009)
Self - Polysomnologist (1 episode, 2009)
Self - Design Engineer, Aerojet (1 episode, 2009)
Self - Swimmer (1 episode, 2009)
Self - Explosives Research Engineer, New Mexico Tech (1 episode, 2009)
Self - Operations Manager, Waste Management (1 episode, 2009)
Self - Fashion Consultant (1 episode, 2009)
Self - National Instruments (1 episode, 2009)
Self - Microbiology Expert (1 episode, 2009)
Self - GM, California Center for Sleep Disorders (1 episode, 2009)
Self - Diving Expert, Dive Lab (1 episode, 2009)
Self - Professor of Neurology, University of California (1 episode, 2009)
Self - Stanford University (1 episode, 2009)
Self - Tandem Hangliding Instructor, Skypuppy Hang Gliding (1 episode, 2009)
Self - Tandem Hangliding Instructor, Bay Area Hangliding (1 episode, 2009)
Self - Professor of Epidemiology, UC Berkeley (1 episode, 2009)
Volunteer Guinea Pig (1 episode, 2010)
Self (1 episode, 2011)
Acrobat / Self - Gymnast (1 episode, 2011)
Volunteer (1 episode, 2012)
Self - Explosives Technician (1 episode, 2012)
Self - Sound Recordist (1 episode, 2012)
Pirate (1 episode, 2012)
Self - Main Unit Cameraman (1 episode, 2012)
Self - Odor Scientist, Monell Chemical Senses Center (1 episode, 2012)
Self - Firearms Consultant (1 episode, 2012)
Self - Indycar Driver (1 episode, 2013)
Zombie (1 episode, 2013)
Extra (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 Volunteer (1 episode, 2016)
Zombie (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)