He was pregnant.
Bobby Sue panicked. How had this happened? Nobody really knows, but Bobby Sue insists that he didn't 'do it'. Word spread around, and soon everyone knew he was pregnant. Rumors spread that his baby was a cross between a cow, lizard, human, carpet, and textbook. People jeered at him, and soon he resorted to telling everyone that he got an abortion.
Eventually, everyone either forgot the whole ordeal or just got bored with teasing Bobby Sue. But, months later, during lunch time, he was sitting on the bench, eating his lunch like everyone else, when suddenly, it was coming out. In the next few moments, he was in a state of confusion, but he made out the sound of someone's voice saying, "Push, Bobby Sue, PUSH!!!", urging him on.
So stuff happened, and Bobby Sue had his baby. It was, indeed, part cow, part lizard, part rug, and part science textbook. It must have been the ugliest baby ever born. And Bobby Sue was ashamed. Now he would have to live up to the sneers and snickers of his peers. He didn't think he could stand the insults.
So Bobby Sue decided he would end it all. He just couldn't stand all the pressure in his life. He was going to commit suicide, but he decided he would do his mom a favour and mow the lawn first. He went out to the garage and brought out the lawn mower, which was a regular push lawn mower. He started it up, and then decided he would enjoy a quick ride before he mowed the lawn. He sat on top of it, and it started rolling down, off his lawn, onto the sidewalk, and into the street.
Meanwhile, Cass, who Bobby Sue had considered a friend after all the events of the year, was driving a semi-trailer along the street that Bobby Sue just rode into on his lawn mower. Seeing Bobby Sue, the first thing that came to Cass' mind was: ROADKILL. He put the pedal to the metal, and zoomed down the street.
Bobby Sue, of course, didn't see Cass zooming towards him, so he was just enjoying himself, yelling "Wheeeeeee!" as he rode into the street. Suddenly.... BOOM!!! They collided, and Bobby Sue was lying there, lifeless, on the street.
So, yeah, Bobby Sue died in this tragic semi-trailer accident, and Cass ended up in a mental institute. Bobby Sue, of course, was to be resurrected sometime later, but thats not til later. You see, the resurrection dudes are on their summer break, and Bobby Sue, although not mentioned in the story, had already died and been resurrected many times. At one point, the janitor killed him for sitting on a table in the school hall. (A mistake that Iziz made too, but first bell had rung, and there was no time for the janitor to kill her). So thats the story of Bobby Sue. The end.