See quotations.
1791. The pine or bull snake is very large, and inoffensive with respect to mankind, but devours squirrels, birds, rabbits, and every other creature they can take as food.W. Bartram, Travels, p. 276.
1878. The bull-snake, so called, [is] an immense thing of four or five feet in length, which gets its name from its blunt head and thick, clumsy body.J. H. Beadle, Western Wilds, p. 133.