Doug Funnie is an imaginative and quirky 12-1/2-year-old who finds himself caught between saving the endangered “monster” of polluted Lucky Duck Lake and his burning desire to take Patti Mayonnaise (Connie Shulman) — his secret crush — to the school dance.

When Doug and his best pal, Skeeter (Fred Newman), discover that the mythical “monster” is real, they also stumble across an elaborate cover-up by one of Bluffington’s leading citizens, industry-Czar Bill Bluff. Adding to Doug’s anxiety is Guy Graham, a slick upperclassman, who wants Patti for himself.