This is Sambandar, one of the Tamil Saivite saints.
Sambandar is one of the sixty-three Nayanmaars (Tamil Saivite saints). Among the sixty-three saints, Sambandar is one of the four (Naalvar) more important ones. The Nayanmaars were instrumental in starting and popularising the devotional (Bakthi) movement in Tamil Nadu.
Sambandar is a historical figure and lived between 630 and 646 CE, yes only for sixteen years. In that period, Sambandar composed nearly four thousand Thevarams (devotional songs) praising Siva.
The story: Sambandar as a child of three years was left unattended by his father as he went to take a bath in a temple tank. Feeling hungry Sambandar started crying. Siva and Parvati appeared before him and gave him a bowl of milk. On his return, Sambandar’s father wanted to know how Sambandar got the milk. Sambandar pointed up indicating the direction from which Siva and Parvati appeared. Hence the mirth and dance with the right-hand index finger pointing upwards.
This Vigraha here is standing on the left leg, now broken, and the right leg is lifted all the way to knee height, as compared to calf height. Quite athletic.
This Vigraha, with the stand, is about 16 cm in height. The Vigraha is from Tamil Nadu and may be dated to the eighteenth century or a bit earlier.
One of the popular images of Krishna is dancing Krishna, with the right hand in Abhaya (protection) mudra and the left hand raised to shoulder level. In those cases, the right leg is lifted to the knee height in a dance move. Very similar to Sambandar. Given the ornamentation tend to be similar, the only way to distinguish is based on the right-hand gesture. A comparison is below.