I will preface this with the obligatory disclaimer: I shit you not.
The complaint was "Visual hallucinations," and the patient was not exactly the sort of individual you would expect to be hallucinating. He was a middle-aged, affluent corporate executive, a sharp and high-functioning individual with no history of either substance abuse or mental illness. He was, therefore, rather perturbed by the little red and green elves he kept seeing all over the place. He knew they weren't real, but they just wouldn't go away. (We attributed the fact that they were red & green to the fact that this case occurred shortly after Christmas.)
The elves, incidentally, were not the weird part.