Fleischer moved West to Los Angeles in the early 1970s where he began performing in comedy clubs. He made his TV debut with an appearance on "Rowan & Martin's Laugh-In" in 1972. Fleischer then spent much of the decade as a regular on a number of short-lived variety and sketch comedy programs and sitcoms. Among the more notable were including "Keep on Trucking" (ABC. 1975), "The Richard Pryor Show" (NBC, 1977) and as a sweathog during the 1978-79 season of "Welcome Back Kotter". In 1983, Alan Thicke tapped Fleischer to be part of the comedy troupe performing sketch segments on his late-night "Thicke of the Night"
Fleischer's feature film career was slower in getting started. He had a supporting role in "Die Laughing" (1980), a Robby Benson vehicle, and also appeared in "Night Shift" (1982), but it was "Roger Rabbit" that gave Fleischer a name, although on-camera feature work remained elusive. One instance was a turn as the cab driver of Anna Chlumsky and Austin O'Brien in "My Girl 2" (1994). But the "Roger Rabbit" connection did snare Fleischer frequent spots on TV variety specials, including "The Prince's Trust Gala" in 1989, and numerous Disney specials, including "Mickey's 60th Birthday" and "Disneyland's 35th Anniversary Celebration". In the 90s, Fleischer contributed humorous segments under the umbrella "The Fleischer Files" to the futuristic cable series, "Next Step" (The Discovery Channel, 1992). He has also performed comedy on many pay TV and cable programs, including HBO's "One Night Stand".