Large hawk-like cuckoo of dense forests, usually foraging in the canopy, where difficult to see. Adult has gray upperparts, streaked white underparts, and long tail with thick dark bars. Juvenile similar but darker brown overall. Large Hawk-Cuckoo very similar but adult averages larger, with a more elongated profile, broader tail bands, and extensive rusty smudging on the neck; juvenile lacks the rusty tone but is densely marked below with arrow-shaped marks, unlike the rounder, sparser marks of juvenile Malaysian. Juvenile Hodgson’s Hawk-Cuckoo also confusingly similar but is likewise more extensively streaked below. Gives two distinct songs, a high “kiwit!” and a rapid-fire series of piping notes.