I think it's fair to debate whether the difference between Scots and English is between two languages or two dialects, but Scots is definitely neither a pidgin

I think it's fair to debate whether the difference between Scots and English is between two languages or two dialects, but Scots is definitely neither a pidgin nor a creole. Pidgins are highly simplified proto-languages that emerge to smooth communication between people with no languages in common. Scots is not highly simplified - it's about as complex as English; they share most but not all of their grammar. Creoles are full languages which arise _suddenly_, generally within a few generations, from a mixture of two or more parent languages. Pidgins often develop into creoles when children grow up speaking them. Scots and English certainly bear influences from many language families, but these influences occurred over many centuries, not a few generations. Scots does vary geographically, having dialects of its own (just like English), but this isn't unusual.