2007-D Wyoming quarter reverse die cap, and struck on an elliptical shaped planchet. The planchet stuck to the anvil die, and was then struck multiple times into the incoming planchets causing it to spread out. It may have been struck on an elliptical clipped planchet, but it's impossible to say with certainty. The shape would make it seem likely that it is in fact struck on an elliptical clipped planchet. Very rare, and dramatic.
PCGS MS-64 blazing white