Gadget mentions that she once found a perpetual-motion machine in the garbage at the science fair, but by that time it had stopped working. The joke with this is that a perpetual-motion machine works forever.
Normie is the first child-villain in the series.
Monty claims that he and a flying squirrel friend of his used to fly over Frostbite Falls looking for mooseberries. This is most likely a reference to Rocky the Flying Squirrel, who lived in Frostbite Falls with his pal, Bullwinkle the Moose. At the time, Buena Vista Home Video owned the distribution rights to The Bullwinkle Show (1959).