I've seen it much more in ancients, but have been shown numerous examples in this thread for modern coins.
Not usually the one to buy a damaged coin, if you like errors and variety's it's a fun coin There is a CUD and a retained cud on the coin not to mention the DDO.
Here is an interesting large cent. An 1802 (S-241) where the engraver managed to make 3 interesting errors while cutting the dies (all on the reverse). "S" cut too low, double bar in the denominator fraction, and no stems...probably the result of a couple of ales too many at the local inn just around the corner from the Philadelphia mint.