Srimad-Bhagavatam: Canto 10 - Chapter 1 - Verse 8
Sanskrit:
वने सञ्चारयन् वत्सान् सरामो बालकैर्वृत: । हन्तुकामं बकं दोर्भ्यां मुखतोऽरिमपाटयत् ॥ ८ ॥
ITRANS:
vane sañcārayan vatsānsa-rāmo bālakair vṛtaḥhantu-kāmaṁ bakaṁ dorbhyāṁmukhato ’rim apāṭayat
Translation:
Another time, when Kṛṣṇa was tending the calves in the forest together with Balarāma and the cowherd boys, the demon Bakāsura came with the intention of killing Kṛṣṇa. But Kṛṣṇa seized this inimical demon by the mouth and tore him apart.