Randy and Howard try to get into a cool zone in the bleachers when watching their school play basketball. When one of the triangle-playing band members is fired, The Sorcerer turns him into a ferocious monster.

When Randy discovers that the Norrisville philanthropist, Hannibal McFist, is his enemy, he has a hard time trying to convince Howard that the one they believed to be their hero is actually an evil villain working with the Sorcerer.

Randy takes a trip to the town's volcano, but it's probably not going to be a nice stop-by.

After a fight between Randy and Howard, a monster attacks during the school's annual routine "monster drill" where Howard is pretending to be the ninja. Randy must find a way to get to his mask and to apologize to his friend.

Randy Cunningham looks for the Skunk Pine in order to restock his smoke bombs. When Randy finds the Skunk Pine, it is stolen by Hannibal McFist to use as a Christmas tree party at McFist Industries. Randy also discovers that Howard is at Hannibal McFist's Christmas party when his father's company was bought by McFist Industries. When Randy infiltrates the Christmas party as a Ninja Santa Claus, he ends up fighting a robotic snowman and an army of robotic Christmas Elves in order to restock his smoke bombs.

After a power outage at school, a Stankified Monster frozen in ice is freed. When Randy de-stanks him, he and Howard learn that his name is Dickie and his monster form was frozen in ice by the Ninja of 1985. When Dickie (voiced by Bobcat Goldthwait) is saddened by this and how he missed his chance with Tawny (voiced by Annie Potts), The Sorcerer takes the opportunity to re-stank him and find out what is the object of his stank.

Franz Nukid, a strange new exchange student, threatens to destroy the Ninja as well as Randy and Howard's friendship which Hannibal McFist takes advantage of.

School Spirit Week turns into a disaster after Howard is possessed by a mythical demon bird called the Tengu which Randy releases.

Randy and Howard seek revenge on a French exchange student who stole their Internet video fame - only to cause him to stank out and create a scene they weren't expecting.

Randy must go with Howard to CluckFest under the threat of Bash Johnson. This won't be easy for Randy since he is afraid of chickens. Meanwhile, Hannibal McFist and Willem Viceroy III unleash a fear-pooping robotic rhinoceros called the Rhinosaurus that forces everyone to confront their worst fear as part of their plot to find the Ninja's greatest fear and take advantage of it.

In order to score a limousine ride with soccer super star Pitch Kickham (voiced by Simon Pegg), the Ninja swipes a pair of shorts to help him win a shoot-out competition. When McFist sends an I.D. Bot to find the shorts, Randy's identity is compromised and Howard must take Randy's place in the competition.

Coach Green brings back an old Norrisville High tradition, Prank Day.

During "Ninja Day" McFist schemes to steal the spotlight by introducing a new hero - Himself.