Several references to this and other movies based on the novel by Bram Stoker, including vampire lore in general, the character Renfield Renquist, and the John Seward Home for the Criminally Insane.
Some scenes take place in "The MacFarlane & Gray Hotel Spa & Convention Center". Dr Wolfe MacFarlane (Henry Daniell) and Cabman John Gray (Boris Karloff) are characters in the movie, based on a story by Robert Louis Stevenson.
The auctioneer introduces himself as Nikolas Pherides, the name of a character played by Boris Karloff in this movie.
Wendy twice mentions Usagi Yojimbo, a comic book character inspired by this movie.
At the puppet convention, there is a 'Bluto' puppet on the table.
Mentioned, in passing, by the Middleman while discussing (Albert) Einstein's brain, currently stored in the fifth-floor archives at Middleman HQ.
Wendy tells The Middleman she's going to "get her Buffy on".
Wendy says, "Hey, I've seen all the 'Blade' movies. I know my way around suck-heads."