It is not a cud because it does not include the rim. It looks like the anomaly may be solder but it is impossible to tell from your photo. Your photo is blurry making it hard to see exactly what is going on. Can you post a clear photo of the obverse and a better one of the reverse?
A cud is a raised portion on a coin caused by a die broken where a piece has broken off. The raised metal is usually a blob and is created when the dies come together (with the planchet between the dies and restrained by a collar). The metal is squeezed up into the void where the piece of the die broke off.
