Valmiki Ramayana Yuddha Kanda Sarga 19 Shloka 15
Original Shlokaदशकोटिसहस्राणिरक्षसांकामरूपिणाम् । मांसशोणितभक्ष्याणांलङ्कापुरनिवासिनाम् ।।6.19.15।।
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कामरूपिणाम् who change form at their will, मांसशोणितभक्ष्याणाम् who eat flesh and blood, लङ्कापुरनिवासिनाम् those residing in the city of Lanka, रक्षसाम् Rakshasas, सहस्राणि: thousands.
"Thousands of Rakshasas inhabit the city of Lanka living on flesh and blood and changing their form at will."