Besides serving as host in every episode, Boris Karloff had roles in five different episodes.
A comic book based upon this series, "Boris Karloff's Tales of Mystery", which was also "hosted" by Karloff, ran from 1962 to 1980, more than a decade after Karloff had died.
The famous Bates Mansion (Psycho house) was featured prominently in an episode starring a very young Rip Torn.
The Munster house exterior and interior is used for one episode staring Edward Andrews.
At the end of each of host's Boris Karloff's introductions he assures the audience without irony that tonight's episode "Is a (real) thriller--As surely as my name is Boris Karloff." In fact his real name was William Henry Pratt.