Doug Funnie finds himself caught between saving the endangered "monster" of polluted Lucky Duck Lake and his desire to take his longtime crush, Patti Mayonnaise, to the school dance.
When Doug Funnie and his friends find a "monster" living in the woods outside their town, they quickly learn that it's actually friendly. Soon after, they find themselves hunted by bad guys, who want to capture the monster for their own evil purposes. In the midst of it all, the school dance is coming up and Doug has to compete with snobby eighth-grader Guy Graham for the attentions of Patti Mayonnaise. Will Doug save the monster from the bad guys and still get to take Patti to the Valentine's Day dance?