Kagu name "Rhynochetos", and the clade name Rhynochetidae, are derived from the Greek "rhis" meaning nose and "chetos" meaning corn, referring to the corn-shaped flaps over the nostrils. The specific name "jubatus" is derived from the Latin "iabatus" meaning crested. The name kagu is derived from the Melanesian names for the species. The species is variously known as the "kavu" or "kagou" in the Kanak languages, and as the "cagou" in French (also used as an alternative spelling in English). The kagu is a ground-living bird, in length. The weight can vary considerably by individual and by season, ranging from .
Kagu crest and wings are used in territorial displays towards other kagu, slightly different displays are used towards potential predators. Territorial disputes may be resolved by fighting using wings and bills, in the wild this seldom results in serious injuries. The kagu is exclusively carnivorous, feeding on a variety of animals with annelid worms, snails and lizards being amongst the most important prey items. Also taken are larvae, spiders, centipedes and insects such as grasshoppers, bugs, and beetles. The majority of the diet is obtained from the leaf litter or soil, with other prey items found in vegetation, old logs and