Think outside the box, the Baku is not from any mythology, it exists because people believed it into existence from the Never Never.
This leads to the terrifying possibility of an entire pantheon coming into existence in a similar fashion to which Harry would be powerless to oppose.
Ronald McDonald, the Hamburglar, Grimace, Mayor McCheese, Birdy The Early Bird, The Fry Kids, The McNugget Gang they all exist in part of the Never Never known as McDonald Land. The one part of the Never Never Harry never wants to be stranded in. Clearly every McDonalds Restaurant borders upon McDonaldland in the NeverNever, so if Harry were ever to open a Gateway in a Restaurant that’s the particular Hell it would open onto.
Of course food in the Never Never has no nutritional value, just like McDonalds in the real world.