"You've seen toons eaten by other toons and show up later in other cartoons, right? Why would toons be able to digest things?"

All perfectly accurate as far as it goes, and a line used to trick many a human tourist into a toony stomach. The sticking point is that while toons can't usually digest other toons, they CAN digest mundane food, and human tourists are just unusually large portions of that food as far as a toon's stomach is concerned.

Lying about this sort of thing to get a meal is stereotypical toon pred behavior. It would be better known and thus less successful except that its hard to report an untrustworthy toon for lying when you only realize they are lying as the gurgling starts.