[3][4] The holotype, an adult female,[a] measures 382 mm (15.0 in) in total length.

The primary annulus count is high (232), whereas the secondary annuli are completely absent.

The coloration is caused by tiny, closely spaced pinkish-cream punctate glands on darker background; when these become closer together and eventually fuse, they give rise to the more pinkish appearance of the head and ventral region.

[2][4] Oscaecilia osae is a subterranean species that occurs in lowland rainforest at elevations below 240 m (790 ft).

There appear not to be major threats to this species, although its distribution and ecology are poorly known.