The thought origin of this popular idiom is rather interesting and factual! Read about it here .  The meaning of the phrase is to attempt to deceive or trick someone.

The expression wild and woolly showed up in print in the Missouri newspaper The Sedalia Daily Democrat, December 1875: "W. A. Palmer, the South Bend, Indiana, murderer and paramour of Dolly Tripp, was for several years resident of Clinton. Bill always was one of the 'wild and woolly' kind and would associate with the demimonde." ( source ) The exact origin of the expression isn't known.