The Fan-tailed Cuckoo has a generally dark slate-grey back and wings with white notches on a dark grey tail. The throat and upper breast are a cinnamon colour and there is a distinctive yellow eye ring and a small white patch on the shoulders. Young birds are duller with subtle brown barring on the breast and brown edges on feathers.
Some Fan-tailed Cuckoos may over-winter in the Geelong region. However, the majority spend the winter in northern Australia and return in early spring. Favourite species that are parasitised include fairy-wrens, thornbills or honeyeaters. Females lay their eggs in nests made by other birds, such as thornbills or fairy-wrens. They feed mainly on insects and their larvae, especially hairy caterpillars.