nirīkṣya tad-vapur alam ambare carat
pradīpta-dṛg bhru-kuṭi-taṭogra-daṁṣṭrakam
jvalac-chikhaṁ kaṭaka-kirīṭa-kuṇḍala-
tviṣādbhutaṁ haladhara īṣad atrasat
nirīkṣya - seeing; tat - of Pralambāsura; vapuḥ - the body; alam - quickly; ambare - in the sky; carat - moving; pradīpta - blazing; dṛk - his eyes; bhru-kuṭi - of his frown upon his eyebrows; taṭa - on the edge; ugra - terrible; daṁṣṭrakam - his teeth; jvalat - fiery; śikham - hair; kaṭaka - of his armlets; kirīṭa - crown; kuṇḍala - and earrings; tviṣā - by the effulgence; adbhutam - astonishing; hala-dharaḥ - Lord Balarāma, the carrier of the plow weapon; īṣat - a little; atrasat - became frightened.
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.