Spotted Crake Bird is slightly smaller than Water Rail, with rather long wings and a longish tail which is often cocked. The bill is short, orange-yellow with a red base of varying intensity in adults, and brownish in juveniles. The upperparts and wings of Spotted Crake Bird are a warm olive-brown, boldly marked with blackish feather centres and covered with a profusion of white spots and arrowheads, appearing both singly and arranged in lines. The crown is brown streaked black, the lores are blackish, and the eyebrow, face, throat and breast are grey, washed brown on the cheeks and breast sides and flecked with small white spots. This spotting extends all the way down the underparts and become larger on the flanks, where they are arranged in vague vertical bars. The undertail coverts are buff and clearly visible when the tail is cocked. The legs are a rather pale green.
Spotted Crake Bird is found in swampy habitats, such as fens and marshes, where it favours dense vegetation, typically of rush together with various grasses and other aquatic plants of low to medium stature (although in Britain it can frequent large reedbeds). It requires shallow water and muddy margins alongside thick vegetation, from which it can sometimes be seen emerging at dawn and dusk.
The advertising call or 'song' of Spotted Crake Bird is very distinctive and produced by both sexes, although more commonly by the male. It consists of a loud repeated "hwhitt!" or "hwatth!", slightly ascending and like a loud echoing drip of water or the sound of a whip cutting through the air. It is repeated continually at a rate of one note per second, particularly at night during the breeding season. Occasionally the female will duet with a male, uttering a similar, softer call. Other vocalizations include a croaking "kwe-kwe-kwe", a sharp "kyak" given when distressed, and another repeated call, "chick-chuck chick-chuck chick-chuck", said to resemble the ticking of a clock. The calls are often the only evidence of this notoriously elusive bird.