Just after Bugs is laughing about the things he did to Yosemite Sam, Sam and Elmer put a bomb in a box and light the fuse, then they give the box to Bugs. When Bugs shakes the box and listens he hears ticking.....so it went from a fuse bomb to a time bomb.
Bugs Bunny tells Yosemite Sam about the time he put eels in his bed, but there is no Bugs Bunny story where this actually happens.