AboutRumbler, a thunder fifi, is Nimbo's older brother, and gives off a blue energy.
Rumbler can unleash a booming shock wave of sound energized with electricity by shouting at a very loud tone. These sound waves are somehow high enough to shatter glass, and yet low and loud enough to become physical and send a target flying. Rumbler is the only thunder fifi known to have perfected this useful technique.
- Music (he carries an MP3 player that was made invisible.)
- Any loud noises
- Thunder (DUH!)