These demons, the followers of Kaṁsa, were expert at persecuting others, especially the Vaiṣṇavas, and could assume any form they desired. After giving these demons permission to go everywhere and persecute the saintly persons, Kaṁsa entered his palace.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
सन्दिश्य साधुलोकस्य कदने कदनप्रियान् । कामरूपधरान् दिक्षु दानवान् गृहमाविशत्
sandiśya sādhulokasya kadane kadanapriyān | kāmarūpadharān dikṣu dānavān gṛhamāviśat
SB 10.4.44