Valmiki Ramayana Yuddha Kanda Sarga 42 Shloka 44
Original Shlokaतथावृक्षैर्महाकायाःपर्वताग्रैश्चवानराः । निजघ्नुस्तानिरक्षांसिनखैर्दन्तैश्चवेगिताः ।।6.42.44।।
1 source checked for this shloka
तथा in the same manner, वृक्षैर्महाकायाः with trees, पर्वताग्रैश्च with mountain peaks, वानराः Vanaras, रक्षांसि at Rakshasas, नखैर्दन्तैश्च with nails and teeth, निजघ्नुस्तानि attacked, वेगिताः swiftly.
Vanaras in the same manner attacked the Rakshasas, with trees and mountains, swiftly and with their nails and teeth.