Yaksas (SB cantos 1 - 4)
Srimad-Bhagavatam
SB Canto 1
SB 1.9.8, Purport:
Śukadeva Gosvāmī (Brahmarāta): The famous son and disciple of Śrī Vyāsadeva, who taught him first the Mahābhārata and then Śrīmad-Bhāgavatam. Śukadeva Gosvāmī recited 1,400,000 verses of the Mahābhārata in the councils of the Gandharvas, Yakṣas and Rākṣasas, and he recited Śrīmad-Bhāgavatam for the first time in the presence of Mahārāja Parīkṣit. He thoroughly studied all the Vedic literatures from his great father. Thus he was a completely purified soul by dint of his extensive knowledge in the principles of religion. From Mahābhārata, Sabhā-parva (4.11) it is understood that he was also present in the royal assembly of Mahārāja Yudhiṣṭhira and at the fasting of Mahārāja Parīkṣit.