Srimad Bhagvata Mahapurana: Book 10: Chapter 15: Verses 23-37
He is a demon of great prowess, disguised as a donkey, 0 Rama, 0 Krsna, and is surrounded by many other donkeys equal in strength to him. The forest is (therefore) never resorted to, 0 Slayer of foes, by men, afraid of that demon, who has tasted the human flesh; nay, it is shunned (even) by herds of cattle and flights of birds. The fruits have never been tasted (by us) before and are sweet-smelling (too); their delicious smell, which has spread all round, can be directly perceived even here. 0 Krsna, make them available to us, whose mind has been lured by their odour. Great is our longing (for them), 0 Rama; let us go (there) if it pleases you. The two almighty Lords heartily laughed to hear the above prayer of Their friends and, accompanied by cowherds, proceeded to the forest of palmyra trees with intent to oblige Their loving companions. Entering the forest and thoroughly shaking the palm trees on all sides with both His arms Balarama, like the young of an elephant, caused their fruits by (sheer) bodily strength to fall down. Hearing the sound of the falling fruits, the demon in the guise of a donkey rushed (towards Balarama,) making the earth's surface quake along-with mountains. Coming up with great speed, the powerful demon struck Balarama in the chest with both of his hind legs; and, giving forth a harsh cry, the wicked fellow ran hither and thither.