One of my Dad's uncles had such a thick hillbilly (not knocking hillbillies, I are one) accent, combined with a vocabulary of words that I swear he made up, well it made him hard to understand at times. Dad used to say he just shook his head yes and no when talking to Dallas, and hoped that he did it in the right places.
I'm TX born and bred, but the fam lived a few of my language-formative years in south GA. I've lost it as I've gotten older, but I know that I still have at least a little bit of an accent. It's most prominent on words with a hard I in them, like right, tight, sight, etc and words like log, dog, fog and whatever that O sound is. A few trips ago to my folks house, my mom pulled out a tape she had found of me reciting a poem from when I was in grade school. Kid me was about 2 sentences in when adult me looked at my mom and said, "what the HECK did I just say?" Apparently back then, I had a knack for turning 1-syllable words into 4 or 5, only I did so at the speed of like 400 words per minute. In retrospect, even I couldn't understand what I was saying. Guess I sounded like Boomhauer when I was a kid.