'Twelve' in the Bible

It stood on twelve oxen, three facing north, three facing west, three facing south, three facing east; and the Sea was set on top of them and all their hindquarters turned inward.

and the one Sea with the twelve oxen under it.

Also, twelve lions were standing there, one on each side of the six steps. Nothing like it had ever been made for any [other] kingdom.

Manasseh was twelve years old when he became king, and he reigned for fifty-five years in Jerusalem.