Bogmonster

n.

Heard in Dublin

A person from the country who is both scary and unintelligible.

In use

Here I tried to rob that cultchie over there but he hadn't a bleedlin clue wot I woz sayin... bleedin bogmonster

Posh English

I attempted to fleece that rustic gentleman over there, but he had not the faintest notion of my discourse. A thoroughly terrifying rural resident.