The term 'SLAYER CASTOR IDAS' is a reference to three characters from Greek mythology. Idas was the son of Aphareus and a prince of Messenia. He was known for his strength and courage, and was a skilled hunter and slayer of wild beasts. Castor was the twin brother of Pollux and the son of Zeus and Leda. He was also a great hunter and warrior, and was renowned for his bravery and skill in battle. Together, Idas and Castor were known as the Dioscuri, or 'sons of Zeus'.