Just looking at this comic, I realise the 'Fun Fact' is pretty much the last pages 'Author Comment'. Turns out I forget the exact wording of a lot of these jokes.
I forget a lot of things.
Like the thing I was going to specifically tell my audience today.
Let's just hope it's not important.
Ah, just remembered! The whole Futurama reference is actually thanks to Forte, who noted the 'drinking beer to break down into energy' thing in his bar information when entering the cameo.
Got the joke. It's just not particularly funny. Robot states the obvious, sarcastic reply. Eh, boring.
The last line of the comic is awkwardly worded. Maybe the joke could have been salvaged if that weren't worded so weirdly.
The joke probably would have been even better if instead of simply going with the trend of "Obvious statement, sarcastic reply", you thought of a response in the last panel that the audience didn't anticipate at all. Perhaps agreeing with him that he had some sort of cancerous growth, then hurried off to have it surgically removed?
Worth noting is the joke is kind of an in joke that is only funny if you know his body is mutated by choice, but nothing condemnable. In general you should try to make jokes kinda open to the audience, but I really can't blame you for it at all.