Commentary for Berakhot 121:14

בשלמא למאן דאמר פרצוף היינו דכתיב (בראשית ה, ב) זכר ונקבה בראם אלא למאן דאמר זנב מאי זכר ונקבה בראם כדר' אבהו דרבי אבהו רמי כתיב זכר ונקבה בראם וכתיב (בראשית ט, ו) כי בצלם אלהים עשה את האדם הא כיצד בתחלה עלה במחשבה לבראת ב' ולבסוף לא נברא אלא אחד

It is quite right according to him who says that it was a face ; that is what is written, "Male and female created He them" (Gen. 5:2). But according to him who said it was a tail, what means "Male and female created He them"? It is [to be explained] according to R. Abbahu who asked : It is written "Male and female created He them," and it is written, "For in the image of God made He man" (ibid. ix. 6). How is this? At first He planned to create two, but in the end only one was created.

Abraham Cohen Footnotes to the English Translation of Masechet Berakhot