All these incarnations of Godhead are either plenary portions or parts of the plenary portions of the purusa-avataras. But Krsna is the Supreme Personality of Godhead Himself - CC Adi 5.79

Expressions researched:
"All these incarnations of Godhead are either plenary portions or parts of the plenary portions of the purusa-avataras. But Krsna is the Supreme Personality of Godhead Himself"

Sri Caitanya-caritamrta

CC Adi-lila

“All these incarnations of Godhead are either plenary portions or parts of the plenary portions of the puruṣa-avatāras. But Kṛṣṇa is the Supreme Personality of Godhead Himself. In every age He protects the world through His different features when the world is disturbed by the enemies of Indra.”

CC Adi 5.79, Translation and Purport

“All these incarnations of Godhead are either plenary portions or parts of the plenary portions of the puruṣa-avatāras. But Kṛṣṇa is the Supreme Personality of Godhead Himself. In every age He protects the world through His different features when the world is disturbed by the enemies of Indra.”

This quotation is from Śrīmad-Bhāgavatam (SB 1.3.28).