Shock Theater (marketed as Shock!) was a package of 52 pre-1948 classic horror films from Universal Studios released for television syndication in October 1957 by Screen Gems, the television subsidiary of Columbia Pictures. The Shock Theater package included Dracula, Frankenstein, The Mummy, The Invisible Man and The Wolf Man as well as a few non-horror spy and mystery films. A second package, Son of Shock, was released for television by Screen Gems in 1958, with 20 horror films from both Universal and Columbia.
Shock Theater usually aired on late night television on weekends, and in many markets was introduced by a costumed horror host; a well-known example was Zacherley (John Zacherle) on Philadelphia's WCAU-TV (as 'Roland') in 1957–1958, and New York's WABC-TV in 1958–1959. Prior to Zacherely's arrival at WABC-TV, Shock Theater was hosted off-camera by ABC Staff Announcer Scott Vincent and three other ABC staff announcers who worked in rotation. Shock Theater continued the American tradition of horror film television shows that originated with Vampira (Maila Nurmi) at Los Angeles KABC-TV in 1954–1955. Shock Theater programs in major cities were often introduced by local hosts in the style of Zacherley or Vampira such as Terry Bennett's Marvin on Chicago's WBKB-TV. With the varying lengths of the features ranging from the 58 minutes of The Cat Creeps to the 99 minute Son of Frankenstein, the host's sequences could pad out the broadcast to a standard time slot.