SB 10.15.31

punar āsādya saṁrabdha
 upakroṣṭā parāk sthitaḥ
caraṇāv aparau rājan
 balāya prākṣipad ruṣā
Word for word: 
punaḥ — again; āsādya — approaching Him; saṁrabdhaḥ — furious; upakroṣṭā — the ass; parāk — with his back toward the Lord; sthitaḥ — standing; caraṇau — two legs; aparau — hind; rājan — O King Parīkṣit; balāya — at Lord Balarāma; prākṣipat — he hurled; ruṣā — with anger.
Translation: 
Moving again toward Lord Balarāma, O King, the furious ass situated himself with his back toward the Lord. Then, screaming in rage, the demon hurled his two hind legs at Him.
Purport: 

The word upakroṣṭā indicates an ass and also one who is crying out nearby. Thus it is indicated herein that the powerful Dhenuka made horrible, angry sounds.