In 1954 he gained his first television role at WCAU-TV in Philadelphia, where he was hired as an actor playing several roles (one was an undertaker) in Action in the Afternoon, a Western produced by the station and aired in the New York City market. Three years later, he was hired as the host of WCAU’s Shock Theater, which debuted on October 7, 1957. As the host, Zacherle appeared wearing a long black undertaker’s coat as the character “Roland,” pronounced “Ro-land”, who lived in a crypt with his wife “My Dear” (unseen, lying in her coffin) and his lab assistant, Igor. The hosting of the black-and-white show involved interrupting the film to do numerous stylized horror-comedy gags parodying the film, an influential change which pioneered a now-standard television genre. In the opening sequence, Zacherle as Roland would descend a long round staircase to the crypt. The producers erred on the side of goriness, showing fake severed heads with blood simulated with Hershey’s chocolate syrup. During the comedy “cut-ins” during the movie, the soundtrack continued to play on the air, while the visual feed switched briefly to a shot of Zacherle as Roland in the middle of a related humorous stunt, such as riding a tombstone, or singing “My Funny Valentine” to his wife in her coffin. The show ran for 92 broadcasts through 1958.

He was a close colleague of Philadelphia broadcaster Dick Clark, and sometimes filled in for Clark on road touring shows of Clark’s American Bandstand in the 1960s. Clark reportedly gave Zacherle his nickname of “The Cool Ghoul.” In 1958, partly with the assistance and backing of Clark, Zacherle cut “Dinner with Drac” for Cameo Records, backed by Dave Appell. At first, Clark thought the recording – in which Zacherle recites humorously grisly limericks to rock and roll accompaniment – was too gory to play on Bandstand, and made Zacherle return to the studio to cut a second tamer version. Eventually both versions were released simultaneously as backsides on the same 45, and the record broke the top ten nationally. Zacherle later released several LPs mixing horror sound effects with novelty songs.

The purchase of WCAU by CBS in 1958 prompted Zacherle to leave Philadelphia for WABC-TV in New York, where the station added a “y” to the end of his name in the credits. He continued the format of the Shock Theater, after March 1959 titled Zacherley at Large, with “Roland” becoming “Zacherley” and his wife “My Dear” becoming “Isobel.” He also began appearing in motion pictures, including Key to Murder alongside several of his former Action in the Afternoon colleagues. A regular feature of his shows continued to be his parodic interjection of himself into old horror films. He would run the movie and have “conversations” with the monster characters. He kept his “wife” in a coffin on stage. His co-star was in a burlap sack hanging from a rope. The on-air conversation consisted of Zacherle repeating the words he heard from the sack.

In a 1960 promotional stunt for his move to WOR-TV, Zacherley—by then, a Baby Boomer idol—staged a presidential campaign. His “platform” recording can be found on the album Spook Along with Zacherley, which originally included a Zacherley for President book and poster set which is highly collectible today. Also, in 1960, he was a guest on CBS-TV’s What’s My Line, on the October 30 broadcast, as the final guest. (Two of the panelists had to disqualify themselves, as they knew his identity.)

Zacherle edited two short story collections for Ballantine Books in 1960. Listed here are their contents.

In 1963, he hosted animated cartoons, as well as Chiller Theatre on WPIX-TV.

In 1965, he hosted a teenage dance show for three years at WNJU-TV in Newark called Disc-O-Teen, hosting the show in full costume and using the teenage show participants in his skits.

In December 1968, Zacherle moved to radio as the morning host for progressive rock WNEW-FM. In the summer of 1969, he became the station night broadcaster (10 PM–2 AM); in June 1971, he switched his show to WPLJ-FM, where he stayed for ten years.

On February 14, 1970 he appeared at Fillmore East music hall in New York City to introduce the Grateful Dead; his introduction can be heard on the album Dick’s Picks Volume 4.

In 1983, he portrayed himself in the feature length horror comedy Geek Maggot Bingo produced and directed by Nick Zedd in sequences shot in Zacherle’s apartment on the Upper West Side.

In 1986, he hosted a direct-to-video program called Horrible Horror, where he performed Zacherley monologues in between clips from public domain sci-fi and horror films.

In 1988, he struck up a friendship with B-movie horror director Frank Henenlotter, voicing the puppet “Aylmer,” a slug-like drug-dealing and brain-eating parasite, one of the lead characters in Henenlotter’s 1988 horror-comedy film Brain Damage, and cameos in his 1990 comedy Frankenhooker, appropriately playing a TV weatherman who specializes in forecasts for mad scientists.

In late 1992, Zacherle joined the staff of “K-Rock,” WXRK, at a time when the roster included other free-form radio luminaries such as Vin Scelsa (with whom he’d worked at WPLJ) and Meg Griffin. He departed in January 1996 when the station switched to an alternative rock format and hired all new jocks.

Zacherle continued to make appearances at conventions through 2015, and his collectibles, including model kits, T-shirts, and posters, continue to sell. The book Goodnight, Whatever You Are by Richard Scrivani, chronicling the life and times of The Cool Ghoul, debuted at the Chiller Theatre Expo in Secaucus, New Jersey, in October 2006. Scrivani and Tom Weaver followed it up with the scrapbook-style “The Z Files: Treasures from Zacherley’s Archives” in 2012.

Zacherley continued to make occasional on-air appearances, usually around Halloween, including a two-hour show at WCBS-FM with Ron Parker on October 31, 2007. (By this point, the 89-year-old was one of the very few people left in radio that was older than the medium itself.) Zacherley and Chiller Theatre returned to the WPIX airwaves on October 25, 2008 for a special showing of the 1955 Universal Pictures science fiction classic Tarantula!.

In 2010, Zacherly starred in the documentary, The Aurora Monsters: The Model Craze That Gripped the World. The film was written and produced by Dennis Vincent and Cortlandt Hull, owner of the Witch’s Dungeon Classic Movie Museum in Bristol, Connecticut. The documentary includes a number of short pieces featuring Zacherly and his puppet co-host Gorgo, of Bill Diamond Productions. The film went on to win a Rondo award.

The Broadcast Pioneers of Philadelphia inducted Zacherle into their Hall of Fame in 2010.

He died on October 27, 2016, at his home in Manhattan at the age of 98.