I first thought it could be a Die Break but since it's a Copper Plated Zinc Cent I will say that it is more of a Plating issue.. a weird Plating Bubble and NOT an extra Letter I Nothing major
Now that I see the full Obverse I can tell you that it is a Die Deterioration Strike. See that semi-circular ring on the field? It's going right through the lettering in LIBERTY. It's nothing. Not a Mint Error.
This penny is like new u would swear it just came right out of the mint my camera phone doesn't serve it any justice
do you think the die deterioration / ridge ring would have helped morph that? it's from the O Mint, located on Mars.