Money (Symbol)
The case full of money symbolizes a wild and unattainable hope for a better life. When Llewelyn finds the money, he thinks of it as "his whole life sitting there in front of him" (18). Sheriff Bell also dreams of money and what wealth affords those who possess it. He assumes that people with money don't have to talk to old ladies on the phone about their cats being stuck up in trees. Money symbolizes an escape from obligation and stress. However, as Llewelyn realizes and as some of the characters know all along, money is "a false God," (182) as Carla Jean says. For Llewelyn, it leads to more trouble than it could ever have been worth.
Coin Toss (Motif)
In a book about unrelenting evil and the temptation of riches, it seems appropriate that the symbol of fate and destiny also be a piece of money. In a blood-soaked chase over 2.4 million dollars, it's quite ironic that the most deadly decider of fate is only worth 25 cents; but as Chigurh points out to the proprietor of the filling station and to Carla Jean, if the coin falls in one's favor, it becomes more than just a coin. It becomes a marker of their fate, a token of proof that their time on earth is not yet up. Chigurh's coin toss becomes a motif because he offers it as an option to people who he's about to ceremoniously kill (as opposed to the many people who he kills without hesitation).
Transponder (Symbol)
The "lozenge"-shaped piece of metal buried inside a hollowed-out stack of one-dollar bills in the briefcase allows Chigurh to trace the location of the money through radio wave transmissions. The transponder symbolizes the futility of hiding and the constant and inescapable surveillance that Llewelyn subjects himself to from the moment he takes the money home. When Llewelyn returns to the scene of the crime and realizes that the cartel will be able to look up his name and address based off the inspection plate on his truck, he thinks of his brother in California, and how even he will suffer for Llewelyn's choices, because these cartel men will never stop hunting until they find their money. The transponder also retroactively scrubs any chance of Llewelyn ever making out clean with the money. One might think if only he hadn't gone back to the caldera to give the man a drink of water, he would be safe, but the presence of the transponder shows that Chigurh would've tracked him straight to his house given enough time.
Cattlegun (Symbol)
Instead of a normal gun, Chigurh prefers to use a pnuematic cattlegun, which shoots a metal bolt out of a tube with highly compressed air from a tank. There are a few reasons why Chigurh might prefer the cattle gun. For one, there's the element of surprise. Half of his victims don't even know what's coming when he presses the pneumatic hose against their foreheads. Secondly, the cattlegun is untraceable, unlike regular guns that leave bullets and shell casings behind. The gun symbolizes Chigurh's ghost-like quality; it is powered by air, thus its power is understated and invisible. Chigurh moves like air, silently and undetected by his enemies. The cattlegun also symbolizes how Chigurh regards his victims: as livestock. He fails to see their humanity and instead sees them only as fleshy obstacles in his path.
Original Sin (Allegory)
When Llewelyn stumbles upon the scene of the cartel massacre, from an allegorical standpoint he's encountering the tree of knowledge of good and evil. He's on the precipice of giving in to a temptation that will make it impossible to go back to the way things were before. When he takes that briefcase full of money, it parallels the story from Genesis, when Eve eats the apple from the tree of knowledge of good and evil, and Adam and Eve are banished from paradise. In the context of No Country for Old Men, paradise for Carla Jean and Llewelyn is living, without a target on their backs, off of the honest work from a nine-to-five job. When Llewelyn calls Carla Jean in Odessa and tells her she needs to flee, she says, "Llewelyn, I dont even want the money. I just want us to be back like we was." When he assures her things will return to normal, she calls the promise "a false God," to which he responds, "Yeah. But it’s real money" (182). Here, McCarthy demonstrates Llewelyn's sustained lust for the money and corruption caused by his possession of it.