You're so fat you sunk Captain Crunch's ship.
You're so fat your blood type is Nutella.
Captain Crunch and Nutella
Explanation
Explain Bear
Alright, listen up, butterball. This joke is sayin' you're so large that you caused a cereal ship to sink just by being near it. Then it says your blood is basically liquid hazelnut chocolate because you're so full of it. Get it? Probably not, given your current state of mental acuity, which is probably close to a squirrel.