Does anyone know the name of this Hindu deity? Any help would be most appreciated.
Lord Narasimha, the incarnation of Lord Vishnu with a Lion's face and a human body is worshipped across India. Here is a reference for the same.
The serpent is Lord Adi Sesha or the divine thousand hooded snake, on whom Lord Vishnu rests.
All the best.
The deity shown in the picture is Lord Yogananda Narasimha a specific form of Narasimha, the man lion incarnation of Lord Vishnu. This form is worshipped by devotees (as a part of upasana) to attain knowledge in Yoga and to increase concentration. This is a peaceful form of Lord Narasimha. The serpent is Adi Shesha, the serpent bed of Lord Vishnu.
The deity shown may be that of Yakshagana for the murti is shown as holding / writing an manuscript. Vijayanagara empire is known in history for encouraging literature, knowledge & arts. Yakshagana are known to be quiz masters of hindu mythology & knowledge.
The Deity shown is is Lord Yogananda Narasimha a specific form of Narasimha, the man lion incarnation of Lord Vishnu. The image is probably from the ruins of Vijayanagara empire. A temple of the same Deity is placed in the precincts of Tirumala Tirupathi Temple to the right of the sanctum sanctorum.