NGC 199X Lincoln Memorial cent struck on a piece of aluminum feeder finger. The coin is entirely aluminum, and is larger than a normal cent, with large chunks of aluminum sticking out. Rare, with 10 examples known to us, including this piece.
The error occurred when the die struck the feeder finger, and tore a piece out of it. Feeder fingers are designed to "break" and are a soft metal so that they do not damage the dies if they are accidentally struck with the dies.
NGC MS-63 with light gray and white surfaces, which is how they almost always come. The aluminum tones over very easily, which is why virtually all feeder fingers have the gray toning on them.