Valmiki Ramayana Yuddha Kanda Sarga 51 Shloka 30

खरयुक्तम् yoked to donkeys, खरस्वनम् braying like donkeys, रथप्रवरम् chariot, आस्थाय mounting, प्रयान्तम् while going, महाघोरम् terrible, भीमदर्शनम् fearful appearance, राक्षसम् at the Rakshasa, अन्तरिक्षागताः going to the sky, घोराः fierce, शकुनाः birds, प्रत्यषेधयन् stood before.

While the Rakshasa was mounted on the chariot and going braying like a donkey, a fearful bird going in the sky stood before his chariot.