According to Homer, "It all started last year during a terrible thunderstorm, when I locked myself out of the house. Sheltering myself with a large piece of sheet metal, I ran for cover under the tallest tree I could find!" A bolt of lightning struck the tree, and a branch fell down. "Something told me this was a very special, very magical, piece of wood that I could make a bat out of." So, he put his homemade football on hold and made himself a bat.
When his co-workers proved hesitant to play softball, Homer motivated them by saying he had a secret weapon, which had them decide to sign up, as they believed his "secret weapon" to be anything from a colossal catcher's mitt to Homer outright zapping the opposing teams with a death beam. During the team's first game, the Plant team fell behind 5-2, with three men on base and Homer up to bat. Homer then revealed his secret weapon, only to be mocked by his team mates. However, Homer managed to hit a home run, starting a winning streak. Eventually, his team mates each tried to find their own magic bats, with Carl trying a piano leg and Charlie using a prosthetic leg.
Mr. Burns however, eventually replaced the team with Major League ringers. Homer, believing he had nothing to worry about as long as he had Wonder Bat, had his bat broken in half by a pitch thrown by Roger Clemens, much to his disbelief.
Homer's Wonder Bat is clearly taken from The Natural, in which a boy decides to carve a bat after seeing an electrical storm breaks off a tree branch, which coincidentally, the same tree his father drops dead near from a case of myocardial infarction. The bat is called the Wonderboy, which is used as the principal good luck bat by Roy Hobbs with his team, the Knights. The destruction of Homer's Wonder Bat is also taken from the film, as in the climax the Wonderboy splinters, and the Knights' bat boy gives Hobbs a bat of his own that he had been working on.