Unlike most of the other featured players, Herman came to the show with an established acting career (as did fellow cast member Phil LaMarr); he had appeared in the films Born on the Fourth of July, Lost Angels, and Let It Be Me.

Herman's MADtv characters included Mike Lawson (Incredible Findings), Generation X anchorman Marsh (X News), and concerned father Joel Linder.

Herman lampooned celebrities and famous figures such as Don Adams (as Maxwell Smart from Get Smart), Tim Allen (as Tim Taylor from Home Improvement), Woody Allen, Nicolas Cage, Bill Clinton, Bob Dole, David Duchovny (as Fox Mulder from The X-Files), Larry Flynt, Tom Hanks (as Forrest Gump and as Jim Lovell from Apollo 13), Larry King, Kenny Kingston, Regis Philbin, Charles Nelson Reilly, John Ritter (as himself and as Jack Tripper from Three's Company), Joel Schumacher, Robert Shapiro, Pauly Shore, Brent Spiner, Patrick Stewart (as Jean-Luc Picard from Star Trek: The Next Generation), and Alex Trebek.

He had a prominent role in the 1999 comedy Office Space as a gangsta rap-loving nerd named Michael Bolton who must endure questions about his relationship to the famous singer.

Let's Be Heroes; The Herald and various characters on Matt Groening's Netflix series Disenchantment; incompetent park ranger Steve Williams on Comedy Central's Brickleberry; and Kevin Crawford on Paradise PD.