I just finished Barbara Hambly’s latest mystery, Dead Water. I love her writings, but - especially in her Benjamin January series - she has a habit of throwing out Latin and Greek quotes with no translation. She has too much respect for me as a reader, I suppose. I can sometimes parse out vague meanings thanks to all the word roots, bases, and affixes I learned for the SAT so long ago, but this one has me stumped.
So, I gotta know. What did Hannibal say?
My Latin is very rusty, but aside from the part about filthy hair I don’t think this is Latin.
I recognise most of the words, although I’m not too sure of the sense. Presumably the context will give it to you. I think it’s something like:
You are a stupid fool and a foul/filthy ball (of excrement, perhaps?)
The words I recognise:
es: 2nd person singular present indicative active of esse, the verb “to be”
blennus: the adjective *blennus, a, um * meaning “foolish, stupid”
vervex: the noun *vervex, vervecis * (m) meaning “fool, dolt”
pila: the noun *pila, pilae * (f), meaning “ball”
fœda: the adjective *fœdus, a, um * meaning “filthy, foul”
“es” is definitely “you are”, and “et” means “and”, as does the suffix “que”.
As for the other words, I don’t have my Latin dictionary with me, but I found most of them here. Scroll down to “Terms of Nonendearment”
I’m guessing “spurius” means “bastard”, since one of the definitions of the English word “spurious” is “of illegitimate birth”.
So I think a reasonable translation might be:
You are a bastard, a doofus and a dolt and a sleazeball.
It’s possible this translation is a bit kind. For instance, I’m betting the meaning of “pila foeda” was a bit harsher in Latin – more like “ball of foulness.”
Perhaps a better translation would be:
You are a bastard, a fool, and an idiot and a turd.
The line also appears to be in dactylic hexameter (dactyl-spondee-spondee-spondee-dactyl-spondee), but I could be wrong. I haven’t studied Latin since high school.
The noun blennus is related to an adjective spelled the same meaning “drooling”. Something like “driveling idiot” is probably intended.
I doubt pila foeda is anything a Roman would have said. I suspect it’s a literal translation of English “slimeball” or “sleezeball”. (In the same way that Latin students find it amusing to use stercus tauri for "bullshit).
Vervex can be translated “dolt” but its primary meaning was “wether” (a castrated ram). So it would imply not just that he’s stupid but that he he has no balls.
So basically, what we have here is something like “you’re a drooling, castrated ball of bastard shit.”
I like it! It has scope and texture. 
I know nothing about Latin, but my guess is that a better phrase would be "elephant turd."
Better in the sense of more accurate, or better in the sense of more insulting? 
If you want to learn some great Latin insults, try reading Catullus. I learned a bunch of excellent insults while studying his poems in high school. One of my favorites was “irrumator”, which literally means one who submits to fellatio. Perhaps that doesn’t sound so bad today, but in Roman times it was a serious insult. It appears in Catullus 10.
Actually, I’ve seen one translation of that poem which actually translates the word as “Clintonizer.” 