In Greek myth, Zeus takes the form of a swan and bull.
They're myths. No, they were never alive, but in some religions they belive they are alive.
They both believe in Gods and Goddesses.
When gods were worshiped, priests wore headdresses depecting the gods in animal form. That is why many gods are seen as half human half animal.
Egyptian gods tended to take the form of animals.
The myths are stories about heroes, gods, demi-gods... Achilles was one of them. So ...
They established gods with power and an interest in intervening in human life, as we have with the various religions today.
Many religions, including most sects of Christianity, Judaism, and Islam believe that God created the earth. Many other polytheistic religions also have creation myths involving gods.
Greek and Roman gods are myths
There are thousands of gods. But they are all different forms of one sole god, Brahma. Some examples are, Vishnu, Shiva, Ganesh, Krishna, Lakshmi
About the gods and what they did.
The Greek gods, the ones who are in the myths.
It was a polytheistic religion. There were many gods. The Romans also adopted foreign deities and their cults, including five Greek ones. Later they associated their gods with those of the Greeks and the Greek myths which went with them. The centerpiece of ancient polytheistic religions was the offering of sacrifices to the gods to appease them. It was thought that natural disasters (such as floods, droughts, earthquakes, volcanic eruptions and animal or human epidemics ) were caused by the ire of the gods who had not been worshiped and honoured.