The episode starts with a narrator telling the story of the Hopping Hessian, the ghost of a mercenary who lost one of his legs during the war and the legend says that every year on Halloween night his ghost rises up from the tomb to search for his missing leg, but the narrator is soon interrupted by a reporter who cuts the story and returns to the news with the announcer wishing everybody a happy Halloween and also telling them to be careful when the Hessian returns to retrieve his leg.
At Rocko's house, Rocko is showing Heffer his inflatable Really Really Big Man Halloween costume. Heffer then shows his costume, which is a tattoo of a pumpkin's face on his belly that glows in the dark. They then rush to Filburt's house, which is a total disaster. They enter to find Filburt hiding under a sheet and they ask him why he doesn't want to go trick-or-treating, he tells them its because of a story his "crazy aunt Gretchen" used to tell him when he was a boy, saying that candy contained poison and that if he touched just one piece, the Hopping Hessian would've come after him and that's why he fears Halloween but Rocko and Heffer take him with them anyway.
At the first house, it doesn't go well when the woman at the door thinks Rocko was already at the house, but in reality, the real Really Really Big Man was already there dressed as Rocko! Then they manage to score an ample amount of candy at Gladys Hippo's house. When Filburt eats one piece of the candy, he finds it to taste absolutely divine - so much so that he goes totally crazy. Filburt then rushes to another house and demands the lady to give him the dish but gets furious when he sees that the dish just has pennies, he then enters the lady's house in search of more confectionary delights, and starts swallowing a whole bag of sugar.
Delirious and hallucinating, Filburt runs out of the house and into the dark woods crossing the old photo house bridge with Rocko and Heffer following him. Heffer tells Rocko that they can't cross there since there was where the one-legged mercenary lost his leg but Rocko tells Heffer that Filburt doesn't know it and that they must go after him.
Rocko and Heffer find Filburt in a cemetery gnawing on a grave marker, (because he was thinking it was a giant bar of chocolate) Filburt then passes out but Rocko and Heffer get him up, Filburt then says that he's never eating candy again and Rocko, Heffer and Filburt leave the graveyard.
Filburt asks them where they are, Heffer then tells him that they are very deep into the dark woods, and that they have also crossed the old photo house but Rocko stops Heffer thinking he (Heffer) could scare Filburt but Filburt says he doesn't care anymore, Rocko and Heffer are then startled by the crack of a stick but Filburt doesn't care at all and just keeps walking (it was just a rabbit and a squirrel trying to scare them) Rocko and Heffer scared keep on walking and they finally get to see the old photo house bridge but the rabbit stops them and tells them to look behind.
They look behind to see a shadowy figure raising a sword in the air and who also appears to have a leg missing, they realize it's the Hopping Hessian who has risen from the tomb to search for his leg, the Hessian then gets out of the cemetery and starts charging at them, Rocko, Heffer and Filburt start running with Filburt behind them (since he's a turtle and is to slow to run) and with the Hessian chasing them, but just when Rocko and Heffer are about to reach the bridge they are intercepted by the Hessian who blocks their way and gets ready to strike at them but Filburt gets them out of the way but gets startled to see that the Hessian was already in front of them, the Hessian then throws his missing leg at Filburt. The last thing we can see is Filburt's broken glasses falling to the river.
The narrator from the beginning of the episode appears saying that the story isn't over yet. The scene cuts to one year later on Halloween night and we can see that Filburt is alright, he then asks a kid which day was and the kid tells him it's Halloween night, Filburt gets happy about it and goes to Rocko's house where he finds Rocko and Heffer looking at the past Halloween's pictures but is startled to see that they are being accompanied by the Hopping Hessian, the viewer then realizes by the way Heffer says playfully "how scary" that the Hopping Hessian never meant to harm them, just to scare them as a Halloween prank.
Heffer then asks the Hessian's missing leg (who is revealed to be Gordon) if they really fought together on the revolution to what the Hessian answers yes, but Gordon says that he's only a friend of a friend of his who helped him move once, Gordon then looks at the hour and say that he and the Hessian must return to the dark woods and Rocko says they also gotta go trick-or-treating but just as everyone is about to leave Filburt, trembling and scared, asks them who took those pictures to which everyone looks surprised and scared (with Heffer breaking the candy bowl in the process).
The orchestral theme that plays during the credits and again at the end of the episode is called "Spooky Scherzo" and is also featured in The Adventures of Pete and Pete's Halloween special. It can be found here: https://www.youtube.com/watch?v=wEE_CY1XKTg
In this episode, it is revealed that the Hopping Hessian is the off-screen voice that says "Yes!" or "No!" when agreeing with Gordon.
When Big Man appears dressed as Rocko, he briefly whistles the Rocko's Modern Life theme song.
This is the first time Gladys is seen without her sunglasses.