Terminal lucidity, the unexpected return of mental clarity and memory shortly before the death of patients suffering from severe psychiatric and neurologic disorders, has raised the curiosity of numerous physicians and laypersons in the past. However, this peculiar phenomenon has received little attention in the recent decades. In previous publications, we have presented overviews of cases of terminal lucidity in various neurologic and psychiatric disorders. In this article, we highlight terminal lucidity in persons with mental disabilities, and focus on one of the most remarkable cases that have been reported. We provide biographical background information about the two principal witnesses who reported this case. It concerns the death of Anna Katharina Ehmer, a 26-year-old woman with severe mental disabilities who lived in an institution for people with mental disorders, and who had allegedly never spoken a single word during her life. Yet, she was reported to have sung dying songs for a half hour before she died. The case was reported by the head of this institution and by its chief physician. We consider it difficult to evaluate the authenticity of the case definitively in retrospect. Nevertheless, there are similar cases and a variety of other anomalous brain-related findings we consider worth investigating. Studies into such anomalous cases might improve our concepts of human brain functioning and of mental processing in persons with mental disabilities, and might be of special value for the dying, the bereaved, and caretakers.