The Beast and the Dragon
Aboard the Elgen ship, Dr. Hatch uses the Biblical prophecy of the Beast and the Dragon to explain the significance of himself and his electric children to Quentin. Essentially, the great beast (with seven heads and ten horns = seventeen) represents the seventeen Glows, who will come to rule over humanity. He himself is the dragon, who gives power, thrones, and authority to the Beast, which he has done by creating the Glows, training them, and giving them authority in the Elgen corporation (and soon, in the world).
The Eagles and the Chickens
There is another allegory that Dr. Hatch uses throughout the series to explain the innate superiority of the electric children. He calls the common population "chickens," who stay tied to their homes and puny ways of life, such as love and morality. The Glows, on the other hand, are "eagles;" they have the right to play with the chickens and use them howsoever they please on account of their strength.
Meihwa
Meihwa is the young Amacarra girl who takes care of Michael at the beginning of the novel while he is recovering. She's kind and innocent, and she comes to care about Michael. She is killed, along with all the other Amacarra, by the Peruvian military, who massacres the tribe for harboring terrorists. She serves as a symbol for the whole tribe; pure, innocent, and simply being kind, is killed by the enemy because of her association with Michael.
RESAT
The RESATs, which are Elgen-invented devices that take away electric powers and have the ability to hurt and even kill the Glows to which they are attached, represent everything the Electroclan is fighting against. It is the anti-Glow, sucking away their powers and causing them to suffer. The fact that it is a machine also evokes the struggle against the Elgen, who use sterile machines and technologies for their evil purposes.
Granadilla
A fruit that Michael and Tessa ate in the Peruvian jungle (known to Tessa as "snot fruit"), granadilla is a symbol of Michael's evolving life. While hiking through the jungle, he disliked the fruit in the same way that he disliked the state of his life (having to trek through the wilderness, lost in a battle against evil). This lifestyle of danger grows on him, though, as he acclimates to his role as a hero. The granadilla likewise grows on him; at the end, he asks Jaime to buy him some from the town before they leave.
