LAST UPDATED Nov 7, 2015. All known cast members noted. Only roles 2013-on noted by name. Info derived from imdb. All known cast members noted.
The Fantastic Four (1978)
Mike Road (Mister Fantastic): died in 2013.
Ginny Tyler (Invisible Girl): died in 2012.
Ted Cassidy (Thing): died in 1979.
Frank Welker (HERBIE, Impossible Man, Magneto): in Scooby-Doo! And WWE: Curse of the Speed Demon (2016), Lego Scooby-Doo!: Haunted Hollywood (2016), Be Cool, Scooby-Doo! (23 episodes 2015-2016), Wander Over Yonder (1 episode 2016), Lego Marvel's Avengers (2016 video game), Open Season: Scared Silly (2015), The Adventures of Puss in Boots (1 episode 2015), LEGO Scooby-Doo! Knight Time Terror (2015), Transformers: Devastation (2015 video game), Lego Dimensions (2015 video game), Lego Scooby-Doo (3 episodes 2015), Scooby-Doo! And Kiss: Rock and Roll Mystery (2015), Curious George 3: Back to the Jungle (2015), Hulk and the Agents of S.M.A.S.H. (1 episode 2015), Scooby Doo and the Beach Beastie (2015), Curious George (11 episodes 2014-2015), Scooby-Doo! Moon Monster Madness (2015), World of Warcraft: Warlords of Draenor (2014 video game), The Simpsons (1 episode 2014), Big Hero 6 (2014), Scooby-Doo! Frankencreepy (2014), Transformers Universe (2014 video game), Transformers: Age of Extinction (2014), Scooby-Doo! Ghastly Goals (2014), Robot Chicken (2 episodes 2014), Avengers Assemble (1 episode 2014), Scooby-Doo! WrestleMania Mystery (2014), Bubble Guppies (1 episode 2014), Mickey Mouse Clubhouse (1 episode 2014), Stan Lee's Mighty 7 (2014); Transformers: The Last Knight (2017) filming.
Dick Tufeld (Opening Narrator): died in 2012.
John Stephenson (Doctor Doom, Magneto, Karnak, Gregson Gilbert): died in 2015.
Don Messick (J.J. Colossal, etc.): died in 1997.
Gene Moss (Trapster): died in 2002.
Hal Smith: died in 1994.
Nancy Wible: died in 2015.
Joan Gerber: died in 2011.
Vic Perrin: died in 1989.
Only voices actors confirmed/probably appearing in at least two episodes noted:
Joan Van Ark (Spider-Woman): in Fallout 4 (2015 video game), The 636 (2014); as Self: Beverly Hills Royal (1 episode 2015), Frogs: Buried in Frogs with Joan Van Ark (2015), Home & Family (1 episode 2014), The Nicole Barrett Show (1 episode 2014), Oprah: Where are They Now? (1 episode 2014).
Bryan Scott (Billy Drew): last known acting roles in 1991, as Additional Voice in 2004.
Larry Carroll (Detective Miller): last known acting role in 2004; as Producer/Self: The 411 (2 episodes 2015, unknown as Writer).
Bruce Miller (Jeff Hunt): last known acting role in 1986.
Lou Krugman (Police Chief Cooper): died in 1992.
Dick Tufeld (Narrator): died in 2012.
Paul Soles (Spider-Man): in The Second Time Around (2015); My 90-Year-Old Roommate (1 episode 2016) in post-production; as Self: Lost Heroes (2014).
Vic Perrin: died in 1989.
Tony Young: died in 2002.
John Milford: died in 2000.
John H. Mayer: in Pee-wee's Big Holiday (2016), Falling Skies (3 episodes 2014-2015), Slow Fade (2015).
Ilene Latter: last known acting role in 1992.
Karen Machon: last known acting role in 1992.
Fred and Barney Meet the Thing (1979)/Fred and Barney Meet the Schmoo (1979-1980)
Only the Thing segments noted
Wayne Norton (Benjy Grimm): in In an Instant (1 episode 2015).
Joe Baker (Thing): died in 2001
Noelle North (Kelly): in Cross the Line (2014); Animalia (2013) completed; last previous known acting role in 2001.
Marilyn Schreffler (Betty/Miss Twilly): died in 1988
John Erwin (Ronald Radford): last acting role in 2005, as Special Effects in 2005.
Art Metrano (Spike): last known acting role in 2001.
Michael Sheehan (Turkey): last known acting role in 2008; as Self: Politics Nation with Al Sharpton (1 episode 2015).
John Stephenson (Dr. Harkness): died in 2015.