Hmm depends for me. Hull (the city I am from) well, people from there are sometimes called codheads.
In Hornsea, anyone from the West yorkshire is called a wezzie. The term for anyone from the south of england (Hull and Hornsea are in Yorkshire, which is the biggest County and is in the north of england) would probably be cunt, but that goes for the whole county, not just Hull and Hornsea.