He was all set to send it to Physical Review Letters, but before he dispatched it, Hetherington gave the paper to a colleague to get one one last set of eyes on the piece. This is when he ran into a strange problem. Hetherington had used the royal "we" throughout the paper. As his colleague pointed out, Physical Review Letters generally only published papers using plural pronouns and adjectives like “we” and “our” if the paper had multiple authors.
Hetherington couldn’t have simply done a find-and-replace to correct the offending articles as it was the year 1975 and the whole paper had been produced on a typewriter.
Unwilling to change all the pronouns, Hetherington portrayed F.D.C. Willard as one of his colleagues at Michigan State and submitted the paper, which was published in issue 35 of Physical Review Letters.
F.D.C. Willard was Hetherington's cat, Chester. Of course just listing “Chester” as a co-author probably wouldn’t fly, so he invented the name F.D.C. Willard. The “F.D.C.” stood for “Felix Domesticus, Chester." Willard had been the name of Chester’s father.
[Source: http://www.atlasobscura.com/articles/in-1975-a-cat-coauthored-a-physics-paper]
