This city was called karuvoor during the time of Sambandar's visit to this temple.

Legend says that Kamadhenu, the mythological cow, meditated upon Siva to receive his blessings and the name Aanilai.

Since Kamadhenu, the cow (locally call Pasu) worshipped the presiding deity, Shiva came to be known as Pasupatheeswarar.

The presiding deity in the main shrine (Moolvar) is a swayambu lingam.

Other festivals include the Eripaththa Nayanar utsavam, Navaratri in September, and Arudra Darisanam in January 22-01-2021 To 24-01-2021 3 days.