The grass coqui or coqui de las hierbas (Eleutherodactylus brittoni) is a species of frog in the family Eleutherodactylidae, endemic to Puerto Rico.Its natural habitats are subtropical or tropical moist lowland forest, subtropical or tropical moist montane forest, subtropical or tropical seasonally wet or flooded lowland grassland, plantations, rural gardens, and heavily degraded former forest.It is threatened by habitat loss.