Looks like a texas cent. Definition: A Texas Cent is a cent with a larger diameter that was damaged intentionally after it left the mint. The normal method is to hammer the cent between 2 pieces of (usually) leather. Commonly seen on cents that have had their plating removed, but not always.
I think that the plating has been removed. The surfaces seem to have a texture instead of luster. You can try to weigh it. The copper plating does not weigh enough to tell much.
Either plating removed, or, one of those grade school chemistry class experiments, utilizing heat, metals, chemicals to change the color of coins. Pennies are most frequently used for such.
It's been de-plated after it was in circulation. Not a genuine 'struck on an un-plated zinc planchet'.