That's actually Chaucerian Middle English, which for some reason has been preserved in Black Vernacular English, as well as among some Southern whites (eg, Lee Harvey Oswald).
I be, you be, he bees conjugation
Celtic English ("I do be openin' the door!"), often stereotypically put in the mouths of pirates and some hillbillies ("be you a Hatfield or be you a Coy rabbit?").