But Pako is soft and squishy, it would only have cracks if it Pako was incredibly hard, like say concrete.

On the comic itself, I really can't say I like it. The flow seems far too quick as it seems Pako decides on his own he wont be killed during Panel 2 when there is no evidence either which way that he will or won't be (especially not early on for sure at any rate.) A speech bubble coming from someone off-screen (AKA- the author) that says "Don't worry I won't" during the second panel would give the rest of the comic a lot more believability and a more sadistic edge to the punchline.