"While the two heads were fairly well formed one of them had only one eye." (Image by law_keven@Wikipedia.)

From the January 17, 1897 Brooklyn Daily Eagle:

“There was a two headed cat at Bellevue hospital, New York, yesterday afternoon. It was dead and in a bottle of alcohol. H.M. Vanderbilt of 249 Jefferson Avenue, this city, took the curiosity to the hospital to show the physicians. The cat was born in his cellar, he said, and lived only a few minutes. While the two heads were fairly well formed one of them had only one eye. The physicians at Bellevue were anxious to have the curiosity left at the hospital, but after exhibiting it, Mr. Vanderbilt brought it back to this city.”