I think it was Artbrooks who said:

A copy of "Eats, Shoots and Leaves" (or is it "Eats Shoots, and Leaves"?) belongs on every desk.

Actually, it should be "Eats shoots and leaves", without a comma after either "eats" or "shoots".   You wouldn't put a comma into "Eats meat and potatoes," would you? (At least I hope not.)

Of course the tagline in the joke would need a comma after both "eats" and "shoots". But we're getting dangerously into analyzing a joke, which is always a mistake.

Dave Oesterreich