Jake: Held by the heel, or, he who deceives.

Jake comes from Jacob, in the bible Jacob is a twin, the 2^nd born. He is born holding his twin's heel, thus explains his name. But Jacob also has another meaning, he who deceives. This might have to do with him stealing his older brother's blessing by deceiving his father. That explains his name origin. Now to why K.A might have chosen it.

Well, while they're fighting the Yeerks they deceive them, don't tell them the whole truth of their identity. And they use it for their own advantage. Jacob is also deceived ,by his Uncle, in the bible, maybe by using the name's history, K.A is hinting at something to come…

Rachel: An Ewe.

Rachel is another biblical figure, the daughter of a shepherd ,she marries Jacob. Jacob mentions falling in love with her because she was beautiful. Thin, with gorgeous eyes, that reminded him of an ewe's eyes.

Maybe K.A was thinking of irony when picking Rachel's name. An Ewe is a relatively weak animal, and Rachel is a fierce fighter. It also might have to do with the Jake/Rachel biblical relationship, which I'll explain later. Of course, by using an Ewe, a weak animal, K.A might be hinting at Rachel's inner weakness…

Jake and Rachel name relationship : In the bible Jacob flees from his home to live with his uncle. He agrees to work for his uncle for seven years, if he gives him Rachel's' hand in marriage. In the end Jacob end's up waiting 14 years for her.

In the story, Jacob and Rachel are cousins. They're also cousins in AM. That might have to do with why K.A choose Rachel as a name, and not Zelda, which means Woman Warrior, or something else. You've also got to keep in mind that their both part Jewish. and both Jacob and Rachel are Hebrew names.

Cassie: Form of Cassandra : Disbelieved by men, or, Prophetess. Form of Catherine: Pure.

I'm going to analyze Cassie's name using the Catherine version. Catherine means pure, which could be K.A using another bit of irony. By reading the books, Cassie believes that she's anything but 'pure'. As for the Cassandra version, well, maybe it will come into play later. We can also assume that K.A wanted to add a bit of her name into the books, but not completely obviously, after all Katherine is a different version of Catherine.

Marco: Warlike.

Marco? Warlike?. Marco, in the first few books, is anything but warlike. Of course, if you look later, Marco becomes ruthless, a good warrior. So it can be seen easily why K.A would choose Marco as a name, in the first few books, or at least until 15, we see Marco as a bad fighter, not at all like a warrior. But after thinking he'd killed his mother, we find him ruthless, willing to sacrifice his own Mother for the fight.

Defiantly 'Warlike.'

So I guess K.A had Marco's character planned out, from the start.

Tobias: Goodness of the Lord.

I think Tobias would laugh out loud at hearing his name. The name seem's out of place for a guy with his past. It seems like nothing good had ever happened to him, no family, no friends, and no real home. And then with the war, and being a nothlit, it seems like lil ol' Tobi hasn't had anything good happen to him. But then again, think about it.

The war may have been a curse for the others, but in a way, it was a gift for Tobias. It gave him friends, family, a place in live. But of course, he's a hawk. But that too gave him freedom. A way of escape, of something good. And even someone to love, Rachel. So, in a way the name wasn't irony at all. It just hinted at something that Tobias couldn't guess at.

Maybe the Lord was good to him after all.

I think Tobias is another one of K.A's hidden things, it hints at something in their character, that you at first you can't guess at. Kind of like it was with Marco.