In the Gaura-ganoddesa-dipika it is said that Kala Krsnadasa was formerly a gopa of the name Lavanga

Expressions researched:
"was formerly a gopa"

CC Adi-lila

Kālā Kṛṣṇadāsa was the ninth cowherd boy.

CC Adi 11.37, Translation and Purport:

The twenty-second devotee of Lord Nityānanda Prabhu was Kālā Kṛṣṇadāsa, who was the ninth cowherd boy. He was a first-class Vaiṣṇava and did not know anything beyond Nityānanda Prabhu.

In the Gaura-gaṇoddeśa-dīpikā (132) it is said that Kālā Kṛṣṇadāsa, who was also known as Kāliyā Kṛṣṇadāsa, was formerly a gopa (cowherd boy) of the name Lavaṅga. He was one of the twelve cowherd boys.