Weisfeld became Newsroom Manager (and later assistant) to Editor-in-Chief Marsha Cohen (formerly of The New York Daily News) and Entertainment Editor Barbara Gordon (who wrote bestseller I'm Dancing as Fast as I Can).
Penthouse Comix sections featured artwork by top comic book talent (Kevin Nowlan, Arthur Suydam, Adam Hughes, etc.).
It featured a number of characters originated by Weisfeld including Libby in the Lost World (co-created with artist Arthur Suydam), which became an international hit in foreign editions and prompted many additional installments of the series.
Writers and artists on the project included Deborah Gregory (who later created Disney's Cheetah Girls), Arthur Suydam (who went to later fame with Marvel Zombies), Walter Moore, and others.
Forbidden Zone published only one issue but this was packed with top comic book and fantasy art talent: Simon Bisley, Richard Corben, Arthur Suydam, Joe Linsner, Larry Stroman, John Cebollero and others.
In 2004, Industry Of War, a comic book property co-created by Jordan Raskin and Horatio Weisfeld (back in 1993), was optioned for film by Alien, Total Recall, Minority Report producer Ronald Shusett.
Starting in 2000 Weisfeld began a long term relationship with Heavy metal Magazine, for whom he developed, wrote, and packaged several character driven properties and HM spin-off brands.
This began with the first installment of Joe In The Future, an ongoing series of short comic book stories written by Weisfeld (with Peter Koch) and illustrated by Trevor Von Eeden.
Heavy Metal began running Joe In The Future as a print series in 2001 after the initial episode appeared as 3-minute internet flash web animation.
Heavy Metal editor Howard Jorofsky suggested Weisfeld allow the print magazine to run the comic book pages from which the webisode had been created.
Painted artwork for the initial segment (Slaughter of the Exterminators) was completed by film production designer Rafael Kayanan (Confessions of a Dangerous Mind, John Carter of Mars).