Question

why was the snake referred to as a king in exile?

Answer 1

The snake was referred as king in exile as it seemed like a king to the poet as he was very glad to have the snake at his water trough. The snake looked vaguely all around and was like a king who was due to be crowned again.

Answer 2

Becoz the sanke awaits to be crowned again when he returns from underworld just like an exile king.