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).
Over the course of Chapter 10, Van Helsing and Dr. Seward try desperately to save Lucy's life, often resorting to blood transfusion. When the two men ask Arthur Holmwood, Lucy's betrothed, to assist them in the quest to save her life, he responds with an ironic hyperbole:
"What can I do?" asked Arthur hoarsely. "Tell me, and I shall do it. My life is hers, and I would give the last drop of blood in my body for her." The Professor has a strongly humorous side, and I could from old detect a trace of its origin in his answer:
"My young sir, I do not ask so much as that - not the last!"
To express the extent of his devotion to Lucy, Arthur utilizes a common hyperbole, stating that he would give "the last drop of blood" in his body to Lucy. In most cases, such a statement is used to emphasize how committed a person is to their cause or to another person; however, all of that person's blood is not literally required for the task. Ironically, and unbeknownst to Arthur, Van Helsing actually does require his blood for the transfusion procedure that will save Lucy's life.
Curiously and ironically, a funeral attendant describes Lucy's dead body as remarkably beautiful at the beginning of Chapter 13:
'She makes a very beautiful corpse, sir. It's quite a privilege to attend on her. It's not too much to say that she will do credit to our establishment!'
The irony of Lucy's extreme beauty, even in death, is not lost on Van Helsing, who later remarks on it. The beauty of Lucy's corpse is almost unearthly, marking her as one of the Un-Dead: much later, when Van Helsing arrives at Castle Dracula to destroy the Count's resting place, he sets his eyes on the bodies of three Un-Dead females, similarly beautiful in death—to a dangerous and seductive degree. Though feminine beauty and purity are portrayed as admirable qualities in both Mina and Lucy (while she was still alive), the beauty of the Un-Dead is neither pure nor admirable. At the heart of this situational irony is the juxtaposition of sexuality and chastity, representative of cultural attitudes towards women in England at the time Dracula was written. Lucy cannot be simultaneously virtuous and overtly sexual, for her morality as a woman is connected to her sexual purity. Vampire Lucy is inhuman, immoral, and sexual; human Lucy is portrayed as pretty, but not for the purposes of sexual provocation.