Cathey's breakout role was on
Children's Television Workshop's
Square One Television, a
sketch comedy-oriented
children's TV series about mathematics. The program aired on
PBS from 1987 to 1992. Cathey later referred to himself and the cast as the "Not Ready for Prime-Time Mathematicians". He also appeared in 1995's
Se7en as the coroner. He played the villain Dirty Dee in the cult comedy film
Pootie Tang and had a regular role on the
HBO series
The Wire as
Norman Wilson during the fourth and fifth seasons. He also worked with
The Wire creator
David Simon on the
Emmy Award-winning miniseries
The Corner; Cathey played a drug addict known as Scalio. He had a recurring role on the HBO prison drama
Oz as unit manager
Martin Querns. In the film
Tank Girl, he played the role of Deetee. He narrated
Aftermath: Population Zero, a
National Geographic Channel special which imagines what
Earth might be like if humanity no longer existed. He played the homeless man Al, murdered by
Patrick Bateman, in the film
American Psycho. He narrated
TLC's
Wonders of Weather, a TV series. On
Between the Lions, he played King Ray in the story of "Rumpelstiltskin" in the episode, "Hay Day". In 2009, Cathey performed in
The People Speak, a documentary feature film that uses dramatic and musical performances of the letters, diaries, and speeches of everyday Americans, based on historian
Howard Zinn's ''
A People's History of the United States''. In Fall 2009, Cathey played the role of Ellis Boyd "Red" Redding in a theatrical production of
The Shawshank Redemption at
Wyndham's Theatre, London. He has made two guest appearances on
Law & Order: Special Victims Unit, as an undercover police officer involved with animal smuggling (episode: "Wildlife") and later as a high-priced defense attorney to a hooker (episode: "
Rhodium Nights"). He also made a guest appearance on
Law & Order: Criminal Intent in the episode "Anti-Thesis" as a college professor suspected of murder. He also played boxing promoter Barry K. Word on the
FX series
Lights Out. In 2013, Cathey began a recurring role as Freddy Hayes, the owner of Freddy's BBQ, in
Netflix's original series
House of Cards, as well as on
Grimm, in the recurring role of
Baron Samedi. His portrayal of Hayes in the second, third, and fourth seasons of
House of Cards earned three Emmy nominations and one win for
Outstanding Guest Actor in a Drama Series. Cathey had expressed a wish to appear in the Irish soap opera
Fair City. Cathey co-starred in
Josh Trank's
Fantastic Four (2015), as
Dr. Franklin Storm, the father of
The Invisible Woman and
The Human Torch. He also played the county sheriff in the city of Rome, WV, in the Cinemax series
Outcast. One of Cathey's final TV roles was portraying
James Lucas in the
Netflix series ''
Marvel's Luke Cage''. ==Death==