The Bushrangers - S1.E35

Alone at Ranger Headquarters, Jerry is overpowered by burglars who take everything movable. Later, Sonny and Skippy come across a group wearing Ned Kelly armour entering a cave. Sonny suspects they are the burglars, but they turn out to be a pop group, 'The Bushrangers', who have set up their instruments in the Park after being driven from their town by neighbours complaining about the noise. The group eventually help catch the burglars after a sloppy mud fight.