A person who intentionally instigates, incites, or starts something, especially one that creates trouble.
One who shapes.
A machine tool in which a single-point cutting tool mounted on a reciprocating ram is traversed across the workpiece linearly. Shapers can generate various shapes, but were most especially employed in generating flat surfaces and keyways. The shaper is nowadays obsolescent, most of its applications being served by milling machines.
A person who designs and builds surfboards.