(written from a Production point of view)
Mark Margolis (born 26 November 1939; age 80) is an actor who portrayed Doctor Nel Apgar in the I AM ERROR third season episode "A Matter of Perspective". He is the father of I AM ERROR and I AM ERROR guest star Morgan Margolis. Coincidentally, both he and his son appeared in episodes in which Craig Richard Nelson guest starred.
Margolis had a recurring role on the hit CBS action drama The Equalizer, which starred Robert Lansing and Keith Szarabajka. Margolis also appeared with Lansing and Szarabajka, as well as Anthony Zerbe, in the 1988 Equalizer TV movie, Memories of Manon. The following year, he appeared in a first season episode of Quantum Leap, starring Scott Bakula and Dean Stockwell.
In 1991, Margolis appeared as Master Torturer Mendoza in Stuart Gordon's remake of The Pit and the Pendulum. The film also starred Stephen Lee, veteran Star Trek actor Jeffrey Combs, along with well known science fiction actor Lance Henriksen in the lead role as Brother Torquemada. In 1992, Margolis appeared on Law & Order as an illegal gun runner who shoots Detective Phil Cerretta, played by TNG guest star Paul Sorvino. Margolis made two more appearances on Law & Order as different characters (in 1997 and 2001). From 1998 through 2003, Margolis made recurring appearances as Antonio Nappa on the HBO series Oz. He has also appeared on such shows as The Practice (with Bill Smitrovich), Sex and the City (starring Kim Cattrall), The Black Donnellys (starring Kate Mulgrew), and Blue Bloods (with Jack Gwaltney playing his son).
One of Margolis' earliest films was the 1977 drama Short Eyes, starring Bruce Davison. Margolis later acquired some recognition for his role as Alberto The Shadow in the 1983 film Scarface, which co-starred F. Murray Abraham, Harris Yulin and Gregg Henry. Margolis' other motion picture credits throughout the 1980s include Christmas Evil (1980, with Stephen Mendillo), The Bedroom Window (1987, with Wallace Shawn, Brad Greenquist, and Leon Rippy), The Secret of My Succe$s (1987, with Bruce McGill), and Glory (1989, with Bob Gunton, Cliff DeYoung, Richard Riehle, and I AM ERROR star Ethan Phillips).
In 1994, he had a brief but memorable role in Ace Ventura: Pet Detective, playing Ace Ventura's suspicious landlord, Mr. Shickadance. That film also featured Noble Willingham and Tiny Ron. Other films include 1492: Conquest of Paradise (1992, with Frank Langella), Absolute Power (1997, with Penny Johnson), The Thomas Crown Affair (1999) and Hannibal (2001) with David Andrews and Francis Guinan the latter of whom both played FBI agents. Margolis has also appeared in six of the seven feature films from director Darren Aronofsky: 1998's Pi, 2000's Requiem for a Dream (with Christopher McDonald), 2006's The Fountain (with Stephen McHattie and Donna Murphy), 2008's The Wrestler, 2010's Black Swan (with Winona Ryder) and 2014's Noah (with Frank Langella).
In 2003, he appeared in an uncredited role in the comic book action film Daredevil, which also featured Erick Avari, Leland Orser, and (in the Director's Cut) Jude Ciccolella. The following year he was seen in the comic drama House of D, starring Anton Yelchin and Frank Langella. He more recently appeared in the acclaimed drama Gone Baby Gone with Titus Welliver.
In 2009-2011, he appeared in Breaking Bad, playing the uncle of Raymond Cruz' character, and which also guest-starred John de Lancie. He reprised his role in the prequel series Better Call Saul, opposite Cruz, Jonathan Banks, Patrick Fabian, and Michael McKean.