The Asian Koel is a large, slender cuckoo measuring 39–46 cm with a long graduated tail, showing striking sexual dimorphism. Adult males are entirely glossy blue-black with a greenish-black sheen, pale greenish-yellow bills, and piercing ruby-red eyes. Females are boldly patterned with dark brown upperparts heavily spotted with white, and whitish underparts densely barred with dark brown. A well-known brood parasite primarily targeting House Crows and Jungle Crows, it remains largely concealed within dense leafy canopies, feeding heavily on ripe wild figs, berries, and caterpillars. In Himachal Pradesh, it is a common summer breeding migrant across the lower Shivalik foothills, open woodlands, mango groves, orchards, and village fringes, typically found up to about 1,200 meters elevation.