An effigy is a statue or a rough model of a person. Effigies can exist for any reason but are most commonly associated to discontent with a person and are seen in protests when protesters make a doll that represents the person and then do with it whatever they think is appropriate.
Secular means that something is separated from religion. In politics, secular means that the government is separated form any type of religion and does not consider religious beliefs when making political decisions. The United States government is secular because the majority of the country are Christians, but the government does not make political decisions based on Christianity.
Polytheistic means the belief in multiple gods. This was commonly seen in history and in myths, especially those for example of ancient Greece or Rome, or Egypt. This includes many gods who represent various things from nature and people pray to them. This was changed when people started believing in a single, omnipotent god.
