Nyctimantis arapapa, also known as Bahia's broad-snout casque-headed tree frog, is a species of frog endemic to the Atlantic Rainforest of southern Bahia, Brazil. The frogs of the genus Nyctimantis are distinguished by a bony plate on top of their heads, referred to as "casque-headed". Casque-headed frogs are characterized by their phragmotic behavior. N. arapapa is further characterized by the long bill-shaped "snout" they possess, similar to that of Triprion petasatus, a head longer than it is wide, and their small size (male snout-vent length 57.4–58.1 mm).[1] This species, and all species of Nyctimantis, use their unique head shape to seal off the leaves of bromeliads, the plant they inhabit solely. This has two known purposes: warding off predators from the frog as well as their young (the male performs this action), and trapping moisture.[2]