In Chapter 1, as he journeys to Castle Dracula for the first time, Jonathan Harker uses both hyperbole and simile to describe Transylvanian superstitions:
I read that every known superstition in the world is gathered into the horseshoe of the Carpathians, as if it were the centre of some kind of imaginative whirlpool; if so my stay may be very interesting (Mem., I must ask the Count all about them.)
Obviously it is not the case that "every known superstition" can be localized to this small portion of the world, and though it may be an "imaginative whirlpool" (as in Harker's simile), it is not the center of all superstitious imagination. This is exaggeration for effect; by using hyperbole and simile in this manner, Stoker primes the reader to associate Transylvania with strange and otherworldly phenomena. Note that fear of the unknown or foreign is common within the characters' narration and dialogue, hinting at broader social/cultural fears in England centered on "aliens" or "non-native" entities.
It is also important to note the dramatic irony in this passage. Readers in the 21st century are aware that Dracula is a vampire before even reading the novel, since the character has become culturally ubiquitous. Though Stoker may not have originally intended this passage to be ironic, contemporary readers will comprehend the irony of Harker wishing to ask Dracula about local superstitions (of which he himself is the subject).
In Chapter 3, Jonathan observes Count Dracula climbing down the castle and describes his movements using a characteristic simile:
I saw the fingers and toes grasp the corners of the stones . . . and by thus using every projection and inequality move downwards with considerable speed, just as a lizard moves along a wall.
This creates a discomfiting image, one of many that evokes Dracula's animalistic nature. Lizards are slippery, moving quickly through small spaces and cracks in walls. Similarly, Dracula is an evasive, serpentine being, able to move with agility in both his corporeal and non-corporeal forms. In such figurative language, Dracula becomes sub-human—a monster—because he moves and behaves like an animal. In certain cases, similes that identify humans with animals can be complimentary (i.e. the strength of a lion, the wisdom of an owl). Such similes are often used in positive characterization, reinforcing desirable qualities that humans, too, may possess. When Stoker compares Dracula to a lizard, however, there is no positive intent. This simile serves the purpose of dehumanizing Dracula, describing movement only without mention of emotions, intellect, or ethics. Consequently, this lizard comparison serves as a juxtaposition, differentiating Dracula from the humans who hunt him.
Towards the end of Chapter 6, Stoker uses a combination of foreshadowing, imagery, and simile to generate a sense of dread and foreboding:
Today is a grey day, and the sun as I write is hidden in thick clouds, high over Kettleness. Everything is grey - except the green grass, which seems like an emerald amongst it . . . . Dark figures are on the beach here and there, sometimes half shrouded in mist, and seem "men like trees walking."
Mina's description of the physical landscape of Kettleness - its menacing ambience - creates a mysterious and unsettling image. Like the "dark figures" obscured by mist, the dark events of the future are obscured from both Mina and the reader, though the ominous mood created by this natural imagery foreshadows some series of menacing supernatural events.
Furthermore, the simile/image of "men like trees walking" reinforces the fact that supernatural forces are at work, conjuring up the image of enchanted trees walking up and down the beach. The statement "men like trees walking" is also an allusion to a Biblical passage in the Gospel of Mark, wherein Jesus heals a blind man. This biblical allusion contributes to the foreshadowing in this passage, implying that something that's unclear will soon be revealed.
Renfield, the patient in Seward's insane asylum, is described using the same animalistic and dehumanizing language often leveled against Dracula. In Chapter 8, Seward describes a fight with his patient:
When we closed in on [Renfield] he fought like a tiger. He is immensely strong, for he was more like a wild beast than a man . . . . With strength and determination like his, he might have done wild work before he was caged.
Renfield, like Dracula, is nearly sub-human and must be dealt with as one would deal with a ferocious beast. In general, anything that is unknown, supernatural, or "other" in this novel (including patients with impenetrable mental illnesses) is treated as subordinate to the morals and tendencies of the main protagonists. This figurative language serves an important purpose, signaling which characters are moral heroes and which are immoral villains. However, it is important for the reader to remain skeptical of the moral judgments they may be asked to make by the author. There exists an extensive and tragic history—both in England as well as in countries around the world—of dehumanizing people who are disabled or mentally ill. Likening Renfield unfavorably to an animal is such an instance of dehumanization, one readers should be critical of.
In one of her letters to Mina in Chapter 9, Lucy uses a simile to describe her appetite:
This strong air would soon restore Jonathan; it has quite restored me. I have an appetite like a cormorant, am full of life, and sleep well.
Lucy's animal simile, in which she likens her appetite to that of a cormorant (a bird of prey that catches and eats fish), is not troubling at face value. Many people, when hungry, use simile or hyperbole (i.e. saying one is hungry enough to eat a whole elephant) to convey the extent of their hunger. One must examine this simile in context to understand its significance. Dracula himself is often likened to animals—frequently predators; thus, by comparing herself to a predatory bird, Lucy marks herself as a future vampire. Furthermore, her appetite and identification with a bird of prey indicate that she herself may soon be "hunting" for human victims as a vampire. In a novel in which the sub-human or the non-human is often placed on the same level as the animal, any figurative language centering animals might serve as a kind of foreshadowing—that is, Lucy's identification with an animal hints that she'll someday be identified with a demonic creature.
At the end of Chapter 12, Lucy tries to kiss Arthur; knowing that she has designs to bite him, Van Helsing prevents this. Lucy's response is as follows, described by Seward with an apt simile:
I kept my eyes fixed on Lucy, as did Van Helsing, and we saw a spasm of rage flit like a shadow over her face; the sharp teeth clamped together.
At this stage, Lucy has transformed almost entirely into her vampiric form. Foiled in her attempt to transform Arthur—or at the very least consume his blood—her features are darkened as if by shadow. This imagery draws the reader's mind to darkness, evoking the nighttime haunted by Dracula and his kind. Thus, in her rage, Lucy becomes less human and less like herself, revealing the vampire slowly taking over her body and soul. The sweet girl described only a few chapters ago would never exhibit such impulsive, animalistic rage; nor would anyone have described her teeth as "sharp." Figurative and literal language combine to distinguish Lucy's past self from her present vampire form. This distinction is important because of human Lucy's purity: female vampires are seductive, sexual, immoral beings. To maintain the purity of her memory, then, Stoker draws a stark contrast between Lucy's former innocence and her current dark, monstrous form.
Towards the end of Chapter 14, Seward remains confused about Van Helsing's thought process, not understanding why Lucy passed away nor how her death is linked with a series of other events. Stoker uses a striking combination of imagery and simile to describe Seward's intellectual position:
At present I am going in my mind from point to point as a mad man, and not a sane one, follows an idea. I feel like a novice blundering through a bog in a mist, jumping from one tussock to another in the mere blind effort to move on without knowing where I am going.
Dr. Seward, an intellectual though he is, finds himself in the same position as the reader - he is similarly in the dark, unable to discern connections between events. Van Helsing prompts him to open his mind to the supernatural (the "unscientific" or "impossible"), an effort which will clear this fog of mystery from his mind and allow him to view the truth. This intellectual fog that Seward (and other characters) are immersed in parallels the literal fog that often rolls in as a premonition of evil—the result of Dracula's dark influence over nature.
In Chapter 16, after blocking the passageway to Lucy's tomb, Seward, Van Helsing, Quincey, and Arthur corner Lucy (in vampire form). Upon viewing her changed appearance, Seward makes an apt allusion:
Never did I see such baffled malice on a face; and never, I trust, shall such ever be seen again by mortal eyes. The beautiful color became livid, the eyes seemed to throw out sparks of hell-fire, the brows were wrinkled as though the folds of the flesh were the coils of Medusa's snakes, and the lovely, bloodstained mouth grew to an open square.
Seward describes the furrows on Lucy's brow as the "coils of Medusa's snakes," alluding to the Greek myth of the monstrous Medusa. This simile/allusion also plays off of the overt sexuality and impurity of the female vampire Lucy (as well as the other female vampires): in the myth, Athena turns Medusa's hair into snakes because she slept with Poseidon in Athena's temple. In other versions of the tale, Medusa was raped by Poseidon and Athena turned her hair into snakes as a form of protection. Medusa's snakes are, in either case, associated with sexuality—not only that, but impurity. Undoubtedly Seward intended the comparison as negative, dismissing the immoral vampire in tandem with Medusa (regardless of her circumstances).
In Chapter 23, the male protagonists corner Dracula at one of his hideouts, flushing him out. Using simile, Stoker describes the Count's appearance in this moment:
As the Count saw us, a horrible sort of snarl passed over his face, showing the eye-teeth long and pointed; but the evil smile as quickly passed into a cold stare of lion-like disdain.
Dracula is here likened to a lion, a simile in line with other figurative language in the novel comparing him to various animals. Lions are predators; in this manner, Dracula is depicted as menacing. Like a lion, he is disdainful of his prey. He does not see Van Helsing and the other protagonists as equal adversaries, but as prey, inferior to him in every respect of the word. Dracula is systematic in his killing—like a lion—having picked his hunting grounds (England) and decided carefully whom to stalk as prey. However, in this moment, the lion simile not only evokes Dracula's menace: it also calls attention to his weaknesses. Lions are accustomed to hunting, but not being hunted. In this scene, the protagonists have tracked Dracula to one of his lairs. He is cornered and weakened; he is a lion, but not for much longer.
There are several instances throughout Dracula of certain individuals being compared to children: most prominently, Mina Harker and Dracula himself. This comparison is a form of diminishing, or infantilization, though purposed towards different ends. Several of the characters describe Dracula's brain as "child-like," including Dr. Seward in Chapter 25:
There I have hope that our man-brains, that have been of man so long and that have not lost the grace of God, will come higher than his child-brain that lie in his tomb for centuries, that grow not yet to our stature, and that only do work selfish and therefore small.
This metaphor, comparing Dracula's brain to that of a child, is intended to dehumanize him—his intellect, both moral and logical, is not up to par with that of the protagonists. In Mina's case, the aim is not dehumanization, but rather to emphasize her innocence (as in Chapter 24):
Mina is sleeping now, calmly and sweetly like a little child. Her lips are curved and her face beams with happiness.
Mina is an emblem of innocence and purity throughout the novel, giving her male compatriots something "worthy to fight for." This simile, while infantilizing, does not serve to dehumanize but rather elevates her morally above the rest.