This is a making of featurette that debuted in 1999 when Universal released its Legacy Collection--classic Universal films like "The Mummy", "Frankenstein" and "Dracula". In fact, they made several making ofs and they were included as special features on the DVDs...and I strongly recommend you find them.
The film is introduced and narrated by Carla Laemmle, niece of the studio chief and who had a small part in the 1931 "Dracula". My wife in particular LOVED her, as she was an adorable 90 year-old lady (she passed away at 104!) and had a sweet style we both enjoyed. In addition to her, various experts appeared, such as Oscar-winning make-up effects man Rick Baker, Bela Lugosi Jr. (who looks amazingly like his famous father) and many others. They did a great job of breathing insight into the making of the film as well as setting the context for it and its major success.
For any fan of Universal horror films, this is an absolute must-- well made, nostalgic and quite complete and enjoyable.