The Canadian Destroyer is a flip piledriver-like maneuver. The name comes from Canadian and TNA wrestler Petey Williams, as he's the person most associated with the move (though according to Williams himself, he's seen evidence of Amazing Red performing it earlier as a variant to a Code Red). It's clearly a piledriver variant, but has usually been ruled as a legal maneuver in lucha libre matches.
The name only makes sense with Williams, but it's stuck as the generic idea for lack of a better idea. Ozz has dubbed this move 'La Darketa when using it as a finish. Teddy Hart used a double underhook version of this move while in AAA.