Osteocephalus mutabor is a species of frogs in the family Hylidae found on the western Andean foothills of Ecuador and south to Ucayali Region of Peru.

Sexual dimorphism is marked: females have a smooth dorsum while males have tubercles hearing spines.

The dorsum is tan coloured and has numerous transverse lines or other markings; the pattern is highly variable.

Juveniles are markedly different and have red eyes, a broad creamy white interorbital bar, and dorsolateral stripes.

[2][4] Spawning has been observed in aquarium where mating took place in shallow water.