Everyone knows that when a cartoon stars Bugs Bunny, Daffy Duck and Elmer Fudd, that it's going to be crazy. In "Beanstalk Bunny", Daffy (as Jack) trades a cow for some beans, which he promptly throws away. Immediately, the beans turn into a beanstalk and Daffy starts climbing it, only to discover that Bugs got caught in it. Obsessed with the "goodies" up above, Daffy kicks Bugs off and continues climbing, but Bugs quickly follows him up. Once they reach the sky, Elmer is the giant. When Bugs and Daffy each claim that the other is Jack, Elmer decides that he'll grind both their bones to make his bread. But Bugs manages to free himself and Daffy. Most of the rest of the cartoon is Elmer chasing the two of them through his castle.
This was probably the only time when Bugs and Daffy had to cooperate (sort of). As always, Daffy is greedy while Bugs is the rationalist, and at the end, we learn how to make a living in the giant's world. Maybe it's not the best Looney Tunes cartoon ever, but Chuck Jones, Mel Blanc and that whole creative team always were able to create something worthy. Fabulous.