> "She looked at him with the yellow, hypnotic eyes of a cobra, and the black cobra-pupil in each eye was as big as a shilling."
Here, the size of Nagaina's pupils being compared to a shilling is a clear exaggeration. Shillings were small coins, and while a cobra's pupils can dilate, they wouldn't be nearly as large as a coin. This comparison emphasizes the intensity of Nagaina's gaze and her powerful, hypnotic nature.