Stupid Smiley was created to be the perfect foil for his brother, Smart Smiley, and his inspiration not only came from the idea of making an opposite number who was just as dumb as Smart is intelligent, but also from wanting to make a character around the basis of a completely silly and goofy face, hence the googly eyes and tongue out look to Stupid's blissfully ignorant visage. I would later go on to create another resident of their world with very much the same kind of face and personality in the form of "Dumb Mutt" of "The Creatures" gang of animal toon villains, but Stupid was the original. I realize the redundancy of both characters, but even well known comics and cartoons are full of that kind of thing, so if they can do it so can I! Besides, one is a dog, and the other is a person, so they are different, so there! Stupid Smiley's symbol is a star, and I honestly can't tell you why this is other than I probably thought that it was a good compliment to the heart that Smart wears. Maybe you could say that, while Smart does all of the thinking and controlling, it's Stupid's moronic antics that make him the real "star." (Perhaps "Pinky and the Brain" was an even bigger influence for these two than I thought they were?)