Crunomys fallax is a small, shrew-like rodent known from Luzon in the Philippines. Records are extremely limited, and its field life remains poorly known.
The paper describes C. fallax as a small, shrew-like rodent with a spiny coat. Short ears, small eyes, and a short tail are given as genus-level traits.
The paper cites only one known specimen of this species, from Luzon. It provides no field observations of diet or activity times.
An extinction-risk assessment has not been added yet.