Fruit bodies are small and white, with thick stipes supporting a "head" shaped like a flattened sphere.

The perineum (outer skin) of the head breaks when the fruit body is mature, which exposes the brown and powdery spores inside.

[5] Onygena corvina is a similar species that grows on the remains of small mammals in owl pellets, on old feathers, or on tufts of animal hair.

He determined that fully grown ("ripe") ascospores can be germinated after a lengthy resting period, but a pretreatment with gastric acids reduced the time required.

These observations confirmed and extended those already published by Ward; taken together, the results indicate that the spores need to pass through the digestive tract of a cow to be viable.

[7] The fruit bodies of Onygena equina grow singly or in tufts or clusters, on rotting horns of cattle and sheep, as well as remains of hooves.