The title is a play on "daredevil".
Bugs Bunny is tricked into being the first rabbit on the moon. When he lands on the moon he finds Marvin the Martian about to blow up the Earth with his Uranium PU36 Explosive Space Modulator. Bugs deals with the Martian and his dog K-9 and steals the modulator. Then he gives it back, intending to blow up Marvin, but blows up the moon instead.
See also List of Bugs Bunny cartoons