When Grandpa activates his snow pill to make it start snowing, "Jingle Bells" is heard on the soundtrack.
The USD 1,000.00 reward for Grandpa, in 1966, would be worth approximately USD 7,792.00 in 2018.
Grandpa mentions that he's 378 years old. That would make 1588 the year he was born.
"Shocking Detective" magazine is obviously based on "Startling Detective," a real magazine that featured lurid tales like the one Herman is reading.
Grandpa tells Pamela, "We Draculas don't drink wine." This is reminiscent of an exchange in the original Dracula (1931) between Mr. Renfield (Dwight Frye) and Count Dracula (Bela Lugosi). Renfield has a glass of wine and notices Dracula does not. Renfield asks, "Aren't you drinking?" to which Dracula replies, "I never drink...wine."