I was in Winchester yesterday and heard for the first time the slang name for a person from Hampshire, Winchester's county - Hampshire hog.
Now, a hog is a pig, and always has been, ever since the word hog entered the language in the Old English period. However, Hampshire is not particularly known for pigs; it is more associated with sheep. Winchester was once an extremely important city in the wool trade. It was one of a handful of English towns designated 'staple towns' in the 14th century, which meant that wool and a few other goods, could be exported from these towns only. Winchester wool and looms were highly prized, according to the British History Online site.
Interestingly, a hog can, or could, also be a sheep (the OED has the definition "a yearling sheep" or a sheep in its second year). Other words for the same thing are hogget, hoggaster and hoggerel. So, a Hampshire hog may indeed be a reference to a sheep.