Since I've been studying to become a CG artist, I've grown to hate these guys more and more.
They're just lazily designed in every single possible way, but especially from a modeling standpoint.
There's no or very little hair, which means they're easier to render, they're flat ovals, which is the easiest shape to simulate because nothing conflicts too much with anything else, and it makes the topology a breeze, meaning they're easily deformed and re-baked. Stretch one out, boom, a whole new one. Give him a fat bottom and skinny top, boom, another one. Tons of characters, one base model. And, my favorite bit, they all wear goggles, which means they don't have to actually model eyes. It's the Yogi Bear thing, where Yogi's collar conceals that his head isn't attached to his body in any way, except in this case, it's the goggles concealing that their eyeballs aren't connected to the rest of their body in any way.
I'm positive someone just shat these guys out, start to finish over the course of a week.