From Le Grelot, 1875.  See How to Be Your Own Cat.

From Lustige Blätter, 1914.

Surprisingly, when groups of people learn How to Be Your Own Cat, the "hundredth monkey" phenomenon is triggered.  From Birmingham Southern's 1961 yearbook.

From Rockford's 1914 yearbook.  You can honestly get better results than in by following the non-surgical procedures in How to Be Your Own Cat.

"The cat, 'I am.'"  To say this yourself in a truly confident tone, see the instant, non-surgical techniques in How to Be Your Own Cat.

From Supernatural Cats, edited by Claire Necker, 1972.

Without pioneers such as these, the secrets of How to Be Your Own Cat could never have been perfected.  From Littleton's 1907 yearbook.

The what and whyfor of these highly occult abominations are explained very thoroughly in How to Hoodoo Hack a Yearbook. 

From Susquehanna's 1901 yearbook.

"The cat changed into a woman."  The principle is the reverse of How to Be Your Own Cat.

From Supernatural Cats, edited by Claire Necker, 1972.

From Le Journal Amusant, 1893.  See How to Be Your Own Cat.

With the latest techniques, you can become your own cat while fully clothed, if you wish.  See How to Be Your Own Cat.  From Le Charivari, 1885.

Not only is this a precursor to How to Be Your Own Cat, but check out that word "metamorphosiological"!  This is the only instance of that word in print that we've found.

From The Woman That Was a Cat, A Metamorphosiological Sketch in One Act by Eugene Scribe, originally presented in 1827.