Spitball

Burleigh "Ol' Stubblebeard" Grimes
Wikipedia - "A spitball is an illegal baseball pitch in which the ball has been altered by the application of saliva, petroleum jelly, or some other foreign substance. Such a pitch presents an additional challenge to the hitter because it causes the ball to move atypically during its approach due to the altered wind-resistance and weight on one side of the ball. Alternative names for the spitball are spitter, mud ball, shine ball, supersinker, vaseline ball (because originally, Vaseline was used to give the ball a little more break), and emery ball, although technically, an emery ball is one where the ball has been abraded in much the same way that the original cut ball had been physically cut (an emery ball is also known as a scuff ball)."
Wikipedia, SF Weekly: A Sports Analogy You Never Thought You'd See: Court's Odd, Split Ruling on Prop. 8 Recalls Spitball Decision in 1920, SABR: Frank Shellenback, In Baseball History (The Spitball), The Spitball King: Gaylord Perry