Probably a black racer - they have a permanently bad temper, though quite harmless.After I treated Me. Blacksnake's tail with triple antibiotic for a week I let him go out by Pop's barn. He took up residence right out behind it in the old McCormick drill. Silly S.O.B. would even stick his head out and hiss at me as I went by mowing. We did notice a decrease in the barn's mouse population.