Nagaraja, the serpent king was carrying the images of five different Lingams, which all got merged into one as the presiding deity at this temple. The temple is believed to have been worshipped by Garuda, sage Kathiru and wife of sage Kashyapa.
https://en.wikipedia.org/wiki/Panchavarnaswamy_Temple
https://www.youtube.com/results?search_query=Panchavarna+Swamy
https://en.wikipedia.org/wiki/Panchavarnaswamy_Temple
https://www.youtube.com/results?search_query=Panchavarna+Swamy