"She Passed Out On Cary! No Wonder . . . She's just discovered his favorite aunts have poisoned their 13th gentleman friend!"
Arsenic and Old Lace - Easter Eggs & Hidden Details
Easter Eggs
The 'Archie Leach' Tombstone
During a scene in the cemetery next to the Brewster house, one of the tombstones clearly bears the name Archie Leach. This is Cary Grant's actual birth name, serving as a brilliant, macabre inside joke about his Hollywood reinvention.
Constant Boris Karloff References
The film features a running gag where characters tell Jonathan Brewster that he looks exactly like Boris Karloff. This is a massive meta-joke, as Boris Karloff originally played Jonathan in the Broadway play and was an investor in the production, profiting from the joke even while absent from the screen.
George Washington Slept Here
Officer O'Hara jokingly asks if George Washington ever slept in the Brewster home. This is an inside nod to Warner Bros. studios, as the massive, expensive Brewster house set was later remodeled and reused for the 1942 film George Washington Slept Here.