Part of the joy of the Muppets is the background characters of their universe. They don't necessarily get a lot of screen time, but when they do, they know how to use it. These characters range from monsters to rats to near-humans, but they're all just as lovable as the main characters, and they have just as much to teach us.
Sweetums. What a name for such a creature. He was ironically named by an evil witch in the Muppet TV special of The Frog Prince (a few years before The Muppet Show debuted). And his demeanor didn't lend itself too well to being regarded as a cuddly creature. But Sweetums, through the years, teaches us that we shouldn't judge by the outside appearance. As a Muppet Monster, he still enjoys some rampaging and mayhem (just take a look at him dancing with Ruth Buzzi!), but at heart, Sweetums reflects his name accurately. He loves to be part of the group, as reflected by his chase of the Muppets across the country in The Muppet Movie, and he is gentle with creatures not-so-large, such as youngster Robin.
Pepe is one of the newer additions to the Muppet world, but he has quickly established himself as a key component, thanks to his off-color remarks and pride in his status as a King Prawn. Pepe is probably a little deceived in his self-perception, but we can most definitely learn about how to have a healthy self-image from him. He refuses to be recognized as less than he is, frequently correcting others when they dare to call him a shrimp. He also has high hopes for himself, and isn't deterred from the path to his dreams by uneasiness or self-doubt.
The Swedish Chef is a classic staple of the Muppet diet, and is one of the special characters to be operated by two Muppeteers, thanks to the requirement that he use both of his hands when teaching an audience how to cook. His concoctions don't quite work out the way he'd prefer, like when the eggs he wants to use bounce like ping-pong balls or when a moose shows up in his kitchen when he's trying to make ... can you guess it? ... chocolate mousse. Despite these set-backs, the Muppets embrace him and his culture, even understanding his garbled version of Swedish. No translation required. They recognize all he has to offer because of his distinctive cultural heritage. He brings diversity to the already-varied Muppet set in his own special way, and we can always stand more diversity in our lives.
"Bork, bork, bork!" -The Swedish Chef