Messmer would subsequently work for Sullivan, who handled the business side of the work, with Messmer handling creative responsibilities. Mayer and Messmer collaborated on the successful animated series The Travels of Teddy, which was based on the life of Teddy Roosevelt. It was never released, but drew the interest of animator Pat Sullivan, though Messmer instead decided to go to work with Henry 'Hy' Mayer, a well-known cartoonist. Messmer signed a deal with Jack Cohn of Universal Studios in 1915 to produce a test film of a character Messmer created called 'Motor Mat'.

One of his comics, Fun, ran as part of the Sunday comics' page for New York World. Inspired by Winsor McCay's animated films, such as How a Mosquito Operates, Messmer began creating his own comics for local newspapers in 1912, the same year he met Anne Mason, whom he married in 1934. Messmer's first love, however, was cartooning. He attended the Thomas School of Art in New York City from 1911–1913, and participated in a work-study program with the Acme Agency, where he did illustrations for fashion catalogs. He had a love of vaudeville and the entertainment industry instilled in him by his parents and teachers beginning at a young age. He attended Holy Family Parochial School. Messmer was born on August 16, 1892, to a German Catholic family in West Hoboken, New Jersey (now Union City).

The extent of Messmer's role in the creation and popularity of Felix is a matter of ongoing dispute, particularly as he only laid his claim to the character after the death of Sullivan, who until that time had received the credit. Otto James Messmer (Aug– October 28, 1983) was an American animator known for his work on the Felix the Cat cartoons and comic strip produced by the Pat Sullivan studio.

Otto messmer