
When the monster School principal tells the Oozo family that they must send one member of the family to school they choose Sigmund. The trouble is thinking he is nothing but trouble Sigmund has run away.
Johnny and Scott bring Sigmund home from the beach and hide him in their clubhouse from Zelda, who invited the sherriff over for dinner. Meanwhile, Sigmund's family gets a visit from their rich Uncle Siggy, who demands to see Sigmund or he'll disinherit the family.
Sigmund falls in love with Fluffy, a dog that belongs to Johnny's girlfriend, Peggy. Sigmund's family schemes to get him back by tricking him into meeting Diana Demon, a sea monster actress who Sigmund has a crush on.