Perhaps you mean 'Tom and Jerry', where there are sometimes overweight characters. But it depends on your specific memory of the cartoon.
The old guy in the Fat Albert cartoon was probably one of the supporting characters, but I can't recall exactly who off the top of my head.
Maybe it's a humorous cartoon where the white fat guy is the main source of comedy with his clumsy actions and funny expressions.
Maybe it's a cartoon about a funny green fat monster who has adventures in a magical world.
It could even be an adventure cartoon where the fat guy and the pig explore strange lands and encounter various characters and obstacles along the way.
Often, a fat guy in a button-down cartoon is shown with a broad smile and maybe some buttons straining to hold. The shirt might be too tight, highlighting his size.
It could be an adventure cartoon where the fat black guy overcomes challenges with his unique skills and personality. There could also be elements of friendship and teamwork involved.
It could be a comedy cartoon where the fat tactical guy gets into funny situations while trying to strategize.
Maybe it's an adventure cartoon where the fat guy with the bow is on a quest. The bow could be his special weapon or tool to overcome challenges.
Well, a cartoon fat ugly naked old guy could be seen as a shock factor or an attempt to break conventional character designs. It might be used to create a strong reaction or make a particular point in the story. However, it's likely to turn off many viewers due to its unconventional and potentially uncomfortable nature.
It might be a comical scene where the old fat guy is having some fun or facing challenges with the inner tube.