From The Hollow Tree Snowed-In Book by Albert Bigelow Paine and illustrated by J. M. Condé, 1910.

Elephant versus dog: which do you wager for the win?  From Chatterbox, 1914.

From Purple Parrot, 1923.

That feeling when you're trying to mind your own business but flowers are staring at you.  From Earlham's 1925 yearbook.

From the Fables of Aesop, told anew by Joseph Jacobs, 1894.

From Ghosts: Life and Death in North India by Ruth Freed.

From The Cat, Being a Record of the Endearments and Invectives Lavished By Many Writers Upon an Animal Much Loved and Much Abhorred by Agnes Repplier, 1912.

Th earliest instances of "Dog is my copilot" we've found in print go back to the mid-1980s.  A decade earlier, we find, "O.k. Duffy ... let's switch to co-pilot."  From the University of Maine at Machias' 1975 yearbook.

From The Current Sauce, 1977.

From Thornton Junior College's 1958 yearbook.

"He didn't mind it so much for the forst 100 times or so, but now it had worked on his Sensibilities until sometimes he feared that he was headed for the Foolish House."  From Hand-Made Fables by George Ade and illustrated by John T. McCutcheon, 1920.

From John Dough and the Cherub by L. Frank Baum and illustrated by John Neill, 1906.

From Chatterbox, 1920.

"An idea for every situation."  From Saint Francis College's 1939 yearbook.

"Don was distacted; he tried to look on both sides at once."  From Chatterbox, 1903.  

From Chatterbox, 1903.  

From The [Thornton] Courier, 1974.

From The Cats' Arabian Nights by Abby Morton Diaz, 1881.