For me, it’s just that something about the delivery and setup feel like they communicate I’m about to experience a very different kind of joke, and so the non-sequitur “I’m piss” catches me completely off guard in a way that makes me cackle

I think humor that depends on seting up and then subverting expectations with something dumb or nonsensical is often very hit or miss. But that sense of humor is increasingly popular, especially among gen z

It’s piss

I agree with what Cris said.

I think this comic would be almost just as funny without the kid crying and yelling at the end. The funniest part to me is the implication that this guy decided his children’s names as babies just for a laugh when introducing them; he probably loves every opportunity to do so, and always makes sure to introduce ketchup first.

(Just to be clear, in case these condiments aren’t popular where you’re from- ketchup is red and mustard is yellow, and they’re often used together, so people see the yellow brother of ‘ketchup’ and think he’ll be named ‘mustard’, but then they find out he’s named ‘piss’ instead)