Kapparot Judaism 101

Maimonides, The Exceptional Mind".
Page 199,
originally the ceremony" of ( KAPPAROT) "was seen as a bribe that was offered to Satan.
A rooster was chosen because;
1.) It was an animal that was not allowed to be sacrificed to God and therefore an appropriate sacrifice for a devil. And,
2.) The masses thought that this bird resembles Satan, it had horns like Satan and its feet resembled the demons feet.
The rooster was slaughtered with the sacrificial formality of laying of hands so that it would be accepted as a suitable sacrifice, bribe by Satan.