Amolops formosus, also known as Assam sucker frog, beautiful stream frog, Assam cascade frog, or hill stream frog,[3] is a species of frog found in high gradient streams of northern India, northern Bangladesh, and Nepal,[3] possibly also Bhutan, although these records may represent confusion between Amolops himalayanus and this species;[3] the latest available IUCN assessment from 2004 treats A. himalayanus as a synonym of A.

The dorsum is green with irregular distinct chocolate-coloured blotches with yellow dots.

[4] Amolops formosus is a rare frog associated with streams and riparian vegetation within tropical evergreen forest[1] at elevations of 1,000–2,508 m (3,281–8,228 ft) above sea level.

[1][4] It is threatened by habitat loss caused by deforestation and dams.

It is present in the Namdapha National Park and Dibang Wildlife Sanctuary in Arunachal Pradesh (India).