Shri Thirumangai Alwar, the youngest and the last of the Alwars, was born in Thirukkurayalur in Tamil Nadu. He is considered as the reincarnation of Lord Vishnu's Sarngam (Divine bow).
Thirumangai Alwar was a highly talented poet and his verses can be found in the Naalaayira Divya Prabandam. His famous works include Thiruvezhuk Kootrirukkai, Periya Thirumozhi with 1084 verses, Thirukkurun Thandakam, Thiru Nedun Thandakam, Siriya Thirumadal and Periya Thirumadal.
Thirugnana Sambandar, the Shaivite Naayanaar saint, a contemporary of the Alwar challenged him in his poetic skills when he visited Sirghazhi. Thirumangai Alwar won the admiration of Sambandar by singing ten verses on Sirghazhi Shri Ramar. He was presented with his Vel (trident) and acknowledging him to be a Naalukavipperumaal.
Hence, in temples, the image of Thirumangai Alwar has a trident in his hands.