Small species of Philautus have puzzled experts for a long time, and only gradually is the fog clearing. Dehling et al. (2016) described a small Philautus as P. nephophilus, which had long been lumped together with P. mjobergi. The type locality of P. nephophilus is the Silau-Silau Trail (6°00’23.2’’ N, 116°32’44.7’’ E), Gunung Kinabalu, Sabah, at 1525 m a.s.l. Philautus nephophilus closely resembles P. mjobergi in overall size, possessing long hind limbs, a relatively broad head, half-webbed toes, and a moderately tubercular dorsal skin texture. Both species, however, are highly variable in their color patterns. They can be distinguished by the shape of the snout, which is acuminate in P. nephophilus and more broadly rounded in P. mjobergi, in both males and females. Consult the original description for side-by-side comparisons.

Philautus nephophilus is a small, stocky frog (snout–vent length in males approx. 16–19 mm; females 20–23 mm). The hind limbs are long; the tibiotarsal joint reaches beyond the tip of the snout when the legs are stretched forward and adpressed to the body. The snout is acuminate (tapering gradually to a sharp point) when viewed from above and below. The snout is shorter than the eye diameter. The heel bears a small conical tubercle; nuptial pads are small but distinct. All digits end in expanded adhesive disks. The toes are only moderately webbed. The iris is reddish in the horizontal sectors, yellow in the upper part, and darkening to greyish brown in the lower part.

The advertisement call consists of a rattling chuckle followed by one or two additional single notes after a distinct interval. The developmental mode has not been documented, but it is likely that this species reproduces by direct development (terrestrial eggs without free-swimming tadpoles).