SpongeBob is the star of the show and one of the most beloved cartoon characters of all time, he, too, is not the brightest. He's just slightly smarter than his buddy Patrick. Yes, he has many other positive qualities that make him lovable, but when it comes to intelligence, he has a low ranking. A big part of this is that he usually acts like a child, which means he is full of imagination but also quite gullible and silly.