I found the following description of the flag of the "Red Rovers," Company A, 5th Mississippi Infantry, in an article written by Joel M. Holbert for the Aberdeen Weekly on July 31, 1903. Holbert had served as a private in Company A, and was badly wounded in the thigh at the Battle of Murfreesboro, Tennessee:

"On the fourth of July our flag which had been made by the ladies of Smithville, and vicinity, was presented to the Red Rover Company. On one side of it was painted the figure of a cotton stalk with a large rattle snake coiled under it, and the words, 'Touch, and I will strike.' On the other side was inscribed the motto, 'Our rights or death.' The presentation was made in an eloquent speech by Miss Fannie McCrummen, later Mrs. G.W. Pennington and was accepted in a speech by Captain Armstrong. The company was in full uniform, armed with old flint-lock muzzle-loading muskets."

I really hope this flag turns up one day, as I would love to see it!