A famous snake as per Mahabharata Adiparva Chapter 35 verse 7.

Once, in hastinapura, Duryodhana mixed the Kalakuda poison in Bhima’s food. Bhima ate it and then everyone went to the river for a bath. Bhima became still when the poison started showing its effect. Duryodhana then tied him up and threw him into the river. He sank to the bottom and then beyond to patala. The snakes there bit him and this had a counter effect to the poison already inside him. He woke up, broke free and killed the snakes. The ones which escaped called Vasuki. As per Mahabharata Adiparva Chapter 127 verses 64-68, it was Aaryaka who mediated.