The Pickles adults decorate their house and set up a haunted house for the trick-or-treaters on Halloween night. They even dress up in costumes. The babies are confused, but Angelica tells them it's Halloween, and brags about getting candy. She shows off the treat the adults will pass out that night: a Reptar Bar, which she was already given one. She says that not only does it taste good, it turns your tongue green! The babies are excited, but Angelica says you have to go in the haunted house in order to get one, and informs them they're far too young.
Didi helps Stu, Drew, and Grandpa Lou set up their little haunted house in the backyard, which has Halloween decorations, a funhouse mirror, and other spooky accessories. She's concerned about the "eyeball" grapes and spaghetti "brains" being too scary, but the men insist this is what Halloween is about. Didi, it turns out, does feel Tommy and the others are too young, and says they can have the haunted house as long as the babies don't go near it.
Trick-or-treating begins and the babies watch from inside. They witness costumed kids going into the haunted house, and coming out moments later screaming in delight, and holding Reptar Bars. Tommy, Phil, and Lil agree they have to get in the haunted house too so they can get Reptar Bars. Chuckie is afraid, but they convince him to come along.
When the adults aren't looking and the haunted house is empty, the babies sneak outside and into the haunted house. They become frightened by it's contents as Didi predicted and try to hide. As this happens, a group of trick-or-treaters that includes Angelica (in an angel costume) arrive and are given Reptar Bars. When they enter the haunted house, they witness Phil and Lil spaghetti-covered reflections in the mirror, Tommy with a sheet over him resembling a ghost, and Grandpa Lou's mask moving on it's own because Chuckie is inside. The trick-or-treaters plus Grandpa Lou become genuinely afraid of the haunted house and flee, leaving behind their bags of candy.
The babies come out of hiding and take the bags of candy into the house where they try out the Reptar Bars. Just like Angelica said, they're delicious and turn their tongues green. Outside, Lou insists to Stu and Drew that they saw genuine monsters inside their haunted house, while Angelica demands somebody goes in and gets her Reptar Bar. Stu and Drew doubt their father while Angelica continues to yell "I want my Reptar Bar!"
The episode made its home video debut, along with "Doug's Halloween Adventure" and The Ren & Stimpy Show episode "Haunted House", on the Nickelodeon FrightFest VHS, released by Sony Wonder in 1994. It was then featured on the 1997 Rugrats VHS Return of Reptar, which also included the episodes "At the Movies", "Reptar on Ice", "Reptar's Revenge", and "Reptar 2010".
The episode made its DVD debut on the manufacture-on-demand DVD release of Rugrats: Season 1 on June 2, 2009. It was then included on the set's subsequent wide retail re-release in 2017.
- A real-life version of the Reptar Bar was produced and sold exclusively at F.Y.E. stores starting in October 2017.