As per sthalapurana, Shankara mangalatthammai, a pativratha used to observe Ekadasi vratha and feed one Brahmachari(bachelor boy) on Dwadasi. Tholakarana, a demon, created hurdles for this. The Lord in the form of Brahmachari killed Tholakarana and came for the feast, hiding the Yagnopavitham (sacred thread) with Krishnajinam (deer skin). The Lord at the request of pativratha gives darshan and continues to give this day , with Lakshmi adorning His chest and hence called Tiruvazhmarban.