The eminent Classicist M. L. West, in his monograph Indo-European Poetry and Myth, specifically the section on what he calls Nymphs and Gnomes, says the following about the κόβαλοι (kóbaloi): “More definitely mischievous and knavish, though in classical times no longer part of living folklore, were the Kerkopes and Kobaloi […]. As for the Kobaloi, they are said to be daimones in the entourage of Dionysus, which suggests something like the Satyrs or Sileni. There are no particular myths about them, but in colloquial Attic κόβαλος meant an impudent rogue or trickster.”
This is right insofar as West clearly differentiates the Kobaloi, with whom no myth is connected, from the Kerkopes, who are said to have pestered Heracles. Is the rest correct, however? Were the Kobaloi really goblin-like daemons who were “part of living folklore” in some earlier period, but “in classical times no longer”? The facts seem to be almost the reverse.
2 Κόβαλοι (kóbaloi) in historical theory and practice
“[I]n colloquial Attic κόβαλος [kóbalos] meant an impudent rogue or trickster.” That is the clearest fact of the matter. It is found in this meaning several times in the colloquial Attic author par excellence, the comic poet Aristophanes, e.g., Κόβαλος εἶ (Kóbalos eî), “You are a rogue!” (Aristophanes, Knights 450).
The word is much less common in more literary Attic, and thus required explanation for later readers. Grammarians supplied them in commentaries, the so-called Scholia, which give explanations such as, “κόβαλοι are robbers with clubs” (Scholia on Knights 270), “κόβαλοι are scoundrels” (Scholia on Frogs 1015), “a κόβαλος is a babbler” (Scholia on Plutus 279). So in fact it seems to have been somewhat unclear to ancient readers of Aristophanes what kind of rogue or ne’er-do-well exactly was meant by κόβαλος.
There is only one source which directly claims that the Kobaloi were daemons, namely a scholium on Aristophanes, Plutus 279: “they are certain rough daemons around Dionysus”. A Byzantine exegete, John Tzetzes, explicitly rejected this: “I have not read of any daemons around Dionysus called Kobaloi, but I know that the most imitative animals are called Kobaloi, and they are a kind of monkey” (commenting on the same passage). In fact, this explanation seems equally wrong, but his rejection still appears to be valid.
Elsewhere, the Aristophanes Scholia point rather in the opposite direction. In the Knights, a noxious sausage-seller recounts a prayer for shamelessness and blathering that he made, invoking Skítaloi, Phénakes, Beréskhethoi, Kóbaloi, Mothōn and Agorá (634–638). As with the rest of the prayer, and the whole speech of the sausage-seller in fact, this is parodic.
The agorá, firstly, is the market-place, a paradigmatically vulgar place. Phénakes are cheats, kóbaloi rogues, and a mothōn an impudent person – the same three words appear together in Aristophanes, Plutus 279–280, as terms of abuse: “You are impudent and a rogue by nature, you cheater!”
Beréskhethoi is more obscure, but at least the ancients agree about its meaning, ‘unintelligent ones’ (anóētoi). The Suda, and a lexical text in papyrus which spells the word Beréskhetoi (Gloss. Oxy. 1801), add that “it was invented by Aristophanes”. This probably means that Aristophanes was the only source for this word in classical literature, while his inventing it is not very likely, in view of its opaque etymology. Probably this too was simply an insult.
The Skítaloi, by contrast, are etymologically transparent, deriving from skitalízō (‘to be lustful’), which makes it more likely that Aristophanes did invent them. A scholium preserved in the lexicon of Hesychius tells us: “He (=Aristophanes) invented the Skitaloi as certain gods (named) after sex and nocturnal lewdness. Theon says that (Aristophanes) invented the name.”
In any case, the scholiasts agree with each other and, I have no doubts, with the truth in saying that Aristophanes was the first to use any of these names referring to divinities, or rather had his character invent such gods: “He coined the names and invented certain shameless daemons; for he stupidly introduces gods that are not real (ouk óntas theoús), as a joke, saying (the words) as if names of gods” (Scholia on Knights 634). The character, “as if to urge and cheer on himself towards shamelessness and boldness, invented gods, as a joke, to whom he prayed” (ibid.). “He invoked these gods as helpers and assistants of wicked people” (ibid.).
If, as has been the common approach to Scholia, and really to ancient sources in general, the interest is primarily in reconstructing religious or mythological traditions behind the text, it is inevitable that inventions and innovations of ancient writers and scholars are misunderstood as either fragments of more ancient beliefs, or else misunderstandings of them. The truth, in all likelihood, is that the Kobaloi as daemons were never part of “living folklore”. Aristophanes coined them as such in one specific passage, and scholiasts riffed on this in later times.
There is nothing here that relates to Proto-Indo-European religion. Much less to the modern term goblin, as others claim even more baselessly; the supposed intermediate form, Latin *cobalus, does not appear to exist at all. Still, since the ancient Greek religion that is actually tangible for us is that which lives on in its records, not a putative original religion behind those records, the obscure afterlife of a throwaway line in Aristophanes is interesting as a piece of Greek religion. It just does not tell us anything about folklore.