The pig's feet with seven coppers are called seven-hole pig's feet. Seven holes in pig's trotters are natural. This kind of trotters is called seven-hole trotters, also called seven-star trotters, seven-star trotters, seven-star elbows, seven-star trotters and seven-star claws. There are seven small holes in the front of pig's trotters, about two millimeters in diameter, and there are some tiny hairs around them.