That is an example of die-deterioration doubling and this is the most famous example. This is very common on 1955 cents, but through the years it's been called the "poor man's double[sic] die" even though it is not a doubled die at all. While common, because of the history with this particular year and this particular example of die deterioration doubling, these coins routinely sell for a premium of a few bucks on Ebay.
That is an example of die-deterioration doubling and this is the most famous example. This is very common on 1955 cents, but through the years it's been called the "poor man's double[sic] die" even though it is not a doubled die at all. While common, because of the history with this particular year and this particular example of die deterioration doubling, these coins routinely sell for a premium of a few bucks on Ebay.
