SB 7.1.33

mātṛ-ṣvasreyo vaś caidyo
 dantavakraś ca pāṇḍava
pārṣada-pravarau viṣṇor
 vipra-śāpāt pada-cyutau
Synonyms: 
mātṛ-svasreyaḥ — the son of the mother’s sister (Śiśupāla); vaḥ — your; caidyaḥ — King Śiśupāla; dantavakraḥ — Dantavakra; ca — and; pāṇḍava — O Pāṇḍava; pārṣada-pravarau — two exalted attendants; viṣṇoḥ — of Viṣṇu; vipra — by brāhmaṇas; śāpāt — because of a curse; pada — from their position in Vaikuṇṭha; cyutau — fallen.
Translation: 
Nārada Muni continued: O best of the Pāṇḍavas, your two cousins Śiśupāla and Dantavakra, the sons of your maternal aunt, were formerly associates of Lord Viṣṇu, but because they were cursed by brāhmaṇas, they fell from Vaikuṇṭha to this material world.
Purport: 

Śiśupāla and Dantavakra were not ordinary demons, but were formerly personal associates of Lord Viṣṇu. They apparently fell to this material world, but actually they came to assist the Supreme Personality of Godhead by nourishing His pastimes within this world.