In Joseph Kesselring’s play, Arsenic and Old Lace, killer Jonathan Brewster returns to his childhood home in Brooklyn where he plans to lay low for a while. The cops are looking all over for him on account of twelve murders (thirteen if you count the one in South Bend who “wouldn't have died of pneumonia if I hadn't shot him!”). Now he’s stuck with Mr. Spinalzo, a cumbersome corpse that he needs to unload, and there’s also the matter of his plastic surgeon pal, Dr. Einstein, fixing his face. The last time Jonathan needed a new mug, the inebriated Einstein had just seen “that movie” and made him look like Boris Karloff!
In 1941, the line, “He looks like Boris Karloff!” brought the house down every night at the Fulton Theater in New York. No wonder. It was a bold self-referential joke. The man who looked like Boris Karloff was, in fact, played by Boris Karloff!