Originally part of an 'issue' of 'Paramount Magazine' which consisted of Bobby Bumps in "Their Master's Voice" (by Earl Hurd), "Feline Follies" and Bud and Susie in "Down the Mississippi" (Frank Moser).
This is generally thought to be the first Felix cartoon, though he's called 'Master Tom' at this stage, and bears only a fairly tenuous resemblance to his later appearance. The story is pretty uninteresting. Tom heads off for a rendezvous with his girlfriend, some mice come out while he's away and cause havoc, and he cops hell when he gets back again. There's little of the wit or inventiveness of the later 20's Felix cartoons, though significantly we do see Tom do some trademark Felix things, like pluck question marks out of the air and turn them into go-cart wheels.
I find this cartoon interesting because to me it opens up the Messmer/Sullivan debate a little. It's more or less accepted now that Felix is Messmer's creation, but the fact that in this earliest supposed appearance he's called 'Tom' lends some credibility to the argument that Felix was a development of Sullivan's 'Thomas Kat' who debuted in 1917. I suspect the truth is that both guys deserve credit for Felix in one way or another, but what would I know? Anyway, a decent cartoon, and historically important, but not mind-altering.