Herzog's Dracula is interesting for a number of reasons. First and most importantly, he is played by Klaus Kinski, who brings his unique combination of spellbinding charisma and sense of the ridiculous to the role. At one point Herzog has him running across an empty town square at night, revelling in the disease and confusion he has introduced into the community. Herzog also makes Kinski carry his own coffins into his ruined castle (no removal van for him), tip-toeing around like a pantomime villain. But he isn't a safe, fun figure, Kinski's commanding presence shines through the heavy make-up. His first confrontation with Harker is edge-of-the-seat stuff.
This mix is all to Herzog's purpose, as his Dracula is more anti-heroic than the all-powerful fiend in the original novel. Herzog is interested in the toll immortality has exerted. It's a "curse". The Count establishes his belligerence in his first conversation with Harker, empathising with the soul of the wolf hunting his prey. But before he signs the contract for his new house, he talks about no longer enjoying the pleasures of youth: fountains and daylight. Living for countless centuries has made him a shadowy, lonely figure.
The familiar theme of aristocratic corruption is touched on. The vampire in his castle is literally sucking the life blood of the peasant population around him. The struggle between reason and superstition also features. Van Helsing, the man with the plan in Stoker's novel, is a neutered figure in Herzog's film. Rather Lucy, who is the victim in the novel, emerges as the preternaturally aware, self-sacrificing saviour. Lucy, played by the luminous Isabelle Adjani, maintains that human beings act on belief rather than reason. Great deeds are often (terminally) foolish. Crosses and superstitions work as wards against nightly terrors. The Count obviously believes in, and is affected by, them.
Adjani is also the only one able to stand up to Kinski directly, calling out his thirst not for sex and violence but for love, the kind not even a god can destroy. Nosferatu's famous shadow creeps over the family home. He peers through the window like the beggar at Christmas. Adjani ensnares Kinski not by seducing him, but by mothering him. Kinski gives suck like a monstrous baby in his final scene. The lone wolf, the predator, just wants to be human.
However, when Harker is revealed as a vampire at the end of the film, he doesn't heed Dracula's lesson. Instead, he grins at the possibilities living death can provide to experience the world to the full. Dracula himself chose to reside in impossibly inhospitable but awesomely beautiful mountains, learning to appreciate the silence of the natural world. Harker rides out seeking the same supra-human vistas, forgetting that he, in time, will also be reduced to the second childishness that finally ruined Dracula.
Just worth noting that allegations have been made about animal cruelty during the making of this film. None of it is clear from the images in the film itself, but it's something that patrons of Herzog should be aware of. Having seen Aguirre, the Wrath of God and imagining the insanely dangerous shoot it must have been (those horses on those leaky rafts...), I'm not entirely surprised Herzog is less than professional in these matters. The man's a genius, but he deserves censure for that.