The Four Horsemen
In chapter 11, Dr. Hatch uses the biblical imagery of the Four Horsemen of the Apocalypse to represent himself and his allies in the days to come. He says that they will have all earthly power and rule over the world with the sword, bringing War, Famine, Plague, and Death to all non-electric humans. This metaphor reveals the depth of Hatch's delusions along with his vision of ultimate domination.
Ostin the Sponge
When McKenna asks Ostin how he knows so much, Ostin responds, "I'm a fact sponge" (Ch. 2). This metaphor is accurate to Ostin's character; he's proud of his ability to remember and apply information, as seen through his intention to not just read but memorize The Art of War later in the novel. It also foreshadows his crisis of self-confidence when he is confronted with the towering genius of Jade Dragon (a nine-year-old girl).
A Pig Hunting for Truffles
"I was amazed at how quickly he'd rooted it out, like a pig hunting for truffles." (Ch. 4)
When entering his room at the ranch for the first time, Ostin immediately locates the snacks in the cupboard and points them out to Michael. This humorous simile emphasizes Ostin's love of snacks but also his skills of observation, which become useful later in the novel.
A Child Playing a Video Game
"Using the MEI is simple. It's like a child playing a video game. He may know how to turn the machine on and even win the game, but he has no idea how the machine actually works." (Dr. Hatch, Ch. 11)
In this speech, Dr. Hatch is explaining the genius and necessity of Jade Dragon. She, unlike the Elgen scientists, actually knows how the MEI machine works (the machine that created the electric children). If Hatch wants to keep making more of them, her expertise is necessary. The simile comparing their current scientists to children playing video games also paints a picture that is supportive of his goals.
Book Club with Hitler
"I was speechless. It was like hearing my mother was in a book club with Hitler." (Ch. 15)
Michael has just learned that "Dr." Jim Hatch was an old coworker of his father, and he had even come over for dinner once. He is temporarily upset at his mother for casually eating with a sociopathic murderer, but then he realizes the obvious: at that point, he wasn't. This simile, however, emphasizes the depravity and megalomaniac ambition of Hatch; it's not unwarranted, either.