This is Vibhișana that has come hither, seeing whom the foremost among the monkeys, from fear of Rāvana's son who, they apprehend, he is, are fleeing away, seized with a panic.
विभीषणोऽयं संप्राप्तो यं दृष्ट्वा वानरर्षभाः। द्रवन्त्यायतसंत्रासा रावणात्मजशङ्कया॥