Fun piece to hang onto for an example of what can happen to coins. Put it with your "silver" cents. LOL
Did this coin come with the other off-center and clipped planchet coin you got recently? Someone was doing some searching of Mint Bagged Coins to find all that. So there may be a possibility your black cent is from the mint. Hang on to it and do some more research on it. Next year you will know more about coins than you do now. And that goes for all of us that have an active pursuit of Numismatics.
Cupric oxide ( Copper(II) oxide) is black, often used in ceramics as a colorant. In chem lab a hot cent exposed to oxygen can form a layer....or maybe a black marker, but very well done if such. Post mint. Jim