Nandaangkovil, formerly known as Thiruntudevankudi during the Thevara period, holds great significance for those born under the "Kataka Rasi" (refers to the astrological sign of Cancer in the Hindu zodiac). According to the Sthala Purana, this temple was the site of a remarkable event involving Goddess Umadevi and the celestial god Indra. The legend states that Umadevi once journeyed from Kailash to worship the deity at this temple, taking the form of a crab. She gathered lotus flowers that grew in the temple's surrounding moat to offer in her devotions. Coincidentally, Indra also came to pay homage to the residing deity at the same time. Upon seeing the crab collecting the lotus blooms he had cultivated in the moat, Indra became enraged, unaware that it was actually Parvati in disguise. In his anger, he climbed atop the Shiva lingam and attempted to slay the crab with his knife as it reached for the flowers. The first strike landed on the crab's jaw, while the second blow fell upon the Shiva Linga's forehead. Desiring to protect Umadevi in her crab form, Shiva created an opening at the apex of the Linga and merged the crab's essence with his own divine being. Realizing his grave error, Indra was filled with remorse and sought forgiveness for his actions. As a result of this sacred history, the temple earned the name Thirundu-devan-kudi. (the place where the 'deva' indira felt remorsefull) Within the temple, a stone pillar bears a carving depicting a crab worshipping a Shiva Linga, forever commemorating this mythical event.

The legend of the Thirundudevankudi temple tells another tale of a Gandharva who was cursed by the sage Durvasa for mocking him during his performance of Shiva puja. As penance for this grave transgression, the Gandharva was transformed into a crab. Seeking redemption and freedom from this existence, the Gandharva beseeched Durvasa for forgiveness. The sage, in his infinite wisdom, instructed the Gandharva to carry out Shiva puja using a lotus flower that bloomed in the moat in the temple premises. Concurrently, Devendra, the king of the gods, also arrived at the temple to offer his own worship to Lord Shiva. Upon seeing the crab utilizing the very lotus flowers he had carefully planted for his own ritual, Devendra flew into a rage and attempted to slay the creature. However, God Shiva, in his boundless compassion, sought to protect the Gandharva from Devendra's wrath. In a miraculous display of divine intervention, God Shiva created an aperture atop the Linga, allowing the Gandharva, still in the form of a crab, to seek sanctuary within. This act of grace not only spared the Gandharva's life but also lifted the curse that had befallen him, granting him liberation from his crustacean form and the opportunity to once again revel in the celestial realms as a divine being.

Deity Karkateswarar

The Shiva linga of the presiding deity Karkateshwarar bears the marks of the aforesaid fascinating legend. The surface of the linga is marred by distinctive cut scars, and a mysterious hole can be observed at its apex. According to 'Vasishta Mahatmiya', an ancient text, a remarkable phenomenon occurs when the Shivalingam is anointed with precisely 21 jugs of milk of 'KArAmpasu' (a pure, full black cow, often associated with spiritual practices and cultural traditions, and is known for its ghee, milk, and other products), during the auspicious confluence of 'Aadi Amavasya' and 'Poora Nakshatra'. It is said that if this ritual is performed at night, an extraordinary sight will unfold as a crab miraculously emerges from the depths of the lingam and makes its appearance atop the sacred stone. This account is further corroborated by the esteemed scholar Dr. U.V. Saminatha Iyer, who asserts that anointing the lingam with a specific offering of ten jugs of milk obtained from a single colored cow will reveal an even more wondrous manifestation—a resplendent golden-colored crab gracefully crawling upon the pinnacle of the Shivalingam.