Love Rollercoaster (S01E11)
Mrs. Eck shows Roberta a slideshow of celebrities who let themselves go over the years. One slide features before and after pictures of Pam Anderson, who puts on a bit of weight as her beauty tarnishes.
Cleveland's Angels (S01E20)
Kendra has a flashback to when she was younger. Here, she was of normal size. As her flashback ended, the transition from past to present, showed her skinny past self morphing into her current fat self. In between frames show brief glimpses of what Kendra looked like in between these times, and while she was putting on a few pounds.
It's the Great Pancake, Junior Brown (S02E04)
Rallo eats all of his Halloween candy in one night. Afterwards, his belly gets bloated.
To Live and Die in VA (S02E17)
A cutaway shows Kendra turning The Brown-Tubbs House into Jabba's Palace. Kendra is shown as rather fatter than before, to better emulate Jabba the Hutt's appearance.
Sex and the Biddy (S03E06)
A buff man gives Cleveland a form fitting girdle, who also reveals to be fat given he wears one too, to give Donna the impression he's really working out. However, Cleveland wears tighter and tighter girdles to keep up with the charade as he gains weight. At the superintendent’s dinner party, when taking a bite of half a shrimp puff, it was enough for Cleveland's final girdle to snap off causing all his fat to show including going to his body.
Dancing With the Stools (S03E10)
While Cleveland and Donna compete in a dance contest, Roberta ends up babysitting Rallo. Unfortunately, Roberta ends up gaining weight from eating nothing but Rallo's junk food, making her clothes too tight. To accommodate this, she changes into Donna's clothes.
Das Shrimp Boot (S03E13)
Cleveland's life flashes before his eyes and his entire aging process is rapidly projected from developing fetus to disintegrating ashes. He's shown gaining weight throughout his growth, most prominently from child to adolescent and from young adult to full grown adult.
Squirt's Honor (S04E18)
Cleveland Jr. reveals to Rallo that he's been sucking his gut in and when he lets it out, the new sash he's wearing that Rallo made snapped that sends one of the badges to crack the camera.