Srimad-Bhagavatam: Canto 4 - Chapter 1 - Verse 41
Sanskrit:
आक्रीडे क्रीडतो बालान् वयस्यानतिदारुण: ।प्रसह्य निरनुक्रोश: पशुमारममारयत् ॥ ४१ ॥
ITRANS:
ākrīḍe krīḍato bālānvayasyān atidāruṇaḥprasahya niranukrośaḥpaśu-māram amārayat
Translation:
The boy was so cruel that while playing with young boys of his age he would kill them very mercilessly, as if they were animals meant for slaughter.