The goddess of misunderstandings. Described as a "trouble-maker". A relative of Hoki, or his female archetype? Or just Hoki in drag, doing the moonlighting thing in order to garner more believers? Raising Steam relates the existence of a Goddess called Pippina, whose badge of office is a golden apple of ominous aspect.
The Greek goddess Eris is the patroness of chaos and discord. (The Romans called her Discordia). "Errata" sounds like a conflation of both names. Eris' greatest achievement was that business with the Golden Apple inscribed "Kallisti" - to the Fairest One - that got the gods of Olympus fighting among themselves, as of course all Gods have infinite egos and all consider themself to be fairest. Eventually the Olympian gods decided to pass this hot potato to a mortal, who was plucked from obscurity to decide which Goddess was fairest and who had title to the Golden Apple. The judgement of Paris led directly to the Trojan War and ten years of destruction, with Eris snggering in the background. It is clear that Eris is a trickster-Goddess....
Errata is also the plural of erratum, which is an error in writing or printing.
Malaclypse is also a priest of Eris in Robert Anton Wilson's Illuminatus! trilogy of novels, where the Goddess is a central character. Another crossover between Discworld and Wilson's manic fantasy?