The color variations of "P. crucifer" are mostly tan, brown, olive green, and gray. Females are lighter-colored, while males are slightly smaller and usually have dark throats. All have a slightly pale yellow coloration on the inside of the thighs. Located by its throat, this frog has a vocal sac that expands and deflates like a balloon to create a short and distinct peeping sound. Only males have the ability to make this loud high-pitched noise, and they use it to attract mates.