Canto 2 -
Ayodhyā-kāṇḍa
Chapter 43: Kausalyā Laments for Rāma, Lakṣmaṇa and Sītā
Text 2.43.2

राघवे नरशार्दूले विषमुप्त्वा विजिह्मताम्।
विचरिष्यति कैकेयी निर्मुक्तेव हि पन्नगी॥

rāghave nara-śārdūle viṣam uptvā vijihmatām
vicariṣyati kaikeyī nirmukteva hi pannagī

rāghave = who has descended from Raghu; nara-śārdūle = the king; viṣam = with the poison; uptvā = having bitten; vijihmatām = of deception; vicariṣyati = wanders about; kaikeyī = Kaikeyī; nirmuktā = that has cast its skin 1; iva hi = like; pannagī = a female snake.

Having bitten the king who has descended from Raghu with the poison of deception, Kaikeyī wanders about like a female snake that has cast its skin.

Kausalyā thus describes Kaikeyī’s extreme cruelty.