Someone who does as they wish, unconstrained by external influences.
Someone who believes in individualism as a sociopolitical system.
Someone who believes in the philosophy of individualism; a solipsist.
One who behaves in a crazy manner.
A pitch thrown with added pressure by the index finger and a twisting wrist motion resulting in a motion to the right when thrown by a right-handed pitcher.
Crazy, offbeat, bizarre, zany, or weird.