An ugly cunt. From British rhyming slang; a munter = an ugly girl. For girl munter = Fergalhunter = an ugly cunt. It's a bit convoluted, but basically "she's a Fergalhunter" = she's an ugly cunt. Try it, it's fun.
In a club; see that bird over there? She's a Fergalhunter. I wouldn't ride her for all the tea in China me old China (more rhyming slang; china plate = mate)