Srimad-Bhagavatam: Canto 10 - Chapter 1 - Verse 27

Sanskrit:

निरीक्ष्य तद्वपुरलमम्बरे चरत्प्रदीप्तद‍ृग् भ्रुकुटितटोग्रदंष्ट्रकम् ।ज्वलच्छिखं कटककिरीटकुण्डल-त्विषाद्भ‍ुतं हलधर ईषदत्रसत् ॥ २७ ॥

ITRANS:

nirīkṣya tad-vapur alam ambare caratpradīpta-dṛg bhru-kuṭi-taṭogra-daṁṣṭrakamjvalac-chikhaṁ kaṭaka-kirīṭa-kuṇḍala-tviṣādbhutaṁ haladhara īṣad atrasat

Translation:

When Lord Balarāma, who carries the plow weapon, saw the gigantic body of the demon as he moved swiftly in the sky — with his blazing eyes, fiery hair, terrible teeth reaching toward his scowling brows, and an amazing effulgence generated by his armlets, crown and earrings — the Lord seemed to become a little frightened.

Purport:

Śrīla Sanātana Gosvāmī explains Lord Baladeva’s so-called fear as follows: Balarāma was playfully acting out the role of an ordinary cowherd boy, and to maintain the mood of this pastime He appeared slightly disturbed by the horrible demoniac body. Also because the demon had appeared as a cowherd boyfriend of Kṛṣṇa’s and because Kṛṣṇa had accepted him as a friend, Baladeva was slightly apprehensive about killing him. Balarāma could also have been worried that since this cowherd boy was actually a demon in disguise, at that very moment another such demon might have been attacking Lord Kṛṣṇa Himself. Thus the omniscient and omnipotent Supreme Lord Balarāma exhibited the pastime of becoming slightly nervous in the presence of the horrible demon Pralamba.