Help?! Name of this cartoon?

Its japanese originally, but is also in english,and is aired on tv from time to time. Its this cartoon about a little girl and her mum and dad going out to the country, when they find this tunnel in the forest. they go through it, and emerge in a different, weirder world. however, when the mum and dad eat some food from a restaurant, they turn into pigs. the only other thing i can remember, is that it also has two twin Granny's in it with heads too big for their body, one is evil, the other is good. there's also a giant baby, a silver dragon that's really a boy, and this weird monster creature that makes gold to lure people, then eats them whole. sounds really weird, but hey, its a weird cartoon. i would be very grateful if you could remember the name.