Ian wakes up one morning to discover something: he has a tapeworm wiggling out of his anus!
The video opens with the Shut Up! screen:
- "Yawn* SHUT UP!"
A voiceover then tells the story of how Ian "ate some bad Mexican food and got hecka sick." Three days later, he awakens to find a tapeworm growing out of his butt.
Ian panics but the tapeworm tells him to chill out. The tapeworm introduces himself as Robbie (voiced by Anthony), and tells him that coming out of asses is what he does. Ian asks Robbie how is he talking only for Robbie to ask Ian back how is "he" talking, confusing him. Robbie says, exactly, and he burps on Ian's gym clothes and turns them into oranges and lemons. Robbie claims indigestion and Ian vomits near the side of his bed.
Ian and Robbie happily watch Glee when Anthony walks in, eating oranges (most likely the gym clothes that Robbie turned into oranges earlier) that taste like "sweaty balls." Ian asks Anthony how does he know what "sweaty balls" taste like. Anthony notices Robbie next to Ian. Ian introduces Robbie as his magical tapeworm. Anthony is surprised that Robbie can talk, only for Robbie to burp at Anthony, causing him to grow boobs. Ian thinks it's just Anthony's shirt budging up, so he tries to remove it but he accidentally crushes them. Anthony tells Ian to stop. But Ian realizes that they are real boobs so he continues to grope Anthony, as he never felt real boobs before, when Anthony angrily tells him to stop.
Anthony goes to a goth's castle for a breast reduction. Anthony tells the goth about Ian and his tapeworm, but the Goth initially thought he was talking about a taint sperm and a stapler. After getting corrected by Anthony, the Goth insists on killing the tapeworm, much to Anthony's confusion. The Goth explains that 4,000 years ago, man lived in harmony with the tapeworms, which at the time were known as the "Mighty Butt Serpents of Ishtar," as they used the tapeworms' powers to build things like the Egyptian pyramids, the Mayan temples, the Great Wall of China, and even McDonalds. But over time, man grew greedy and destructive, using the tapeworms' powers for evil. To save humanity, the goths used their spiritual powers and maximum strength laxatives to banish and destroy them once and for all. The goth then discovers Anthony was asleep the entire time, making the Goth slap Anthony before telling that they must kill the "magic stapler." Anthony reminds the goth about the breast reduction, only for the goth to compliment Anthony's boobs.
Ian is at home eating, asking why he has been very hungry lately. Robbie burps and transforms a teddy bear into a pile of The Wizard of Oz DVDs. Robbie says it is a great movie but Ian admits he has never seen it. Robbie makes fun of him but Ian tells him to shut up.
The goth comes in through the door to eliminate Robbie. The goth blows on a horn, saying that it will make Ian lose his bowels and "eject the butt serpent." Ian manages to hold his bowels tight enough while a mailman hears the noise and loses control of his bowels. Robbie burps at the goth to stop the horn. At first, the goth is unfazed until he realizes that Robbie turned his horn into a full length Rebecca Black album. The goth cannot take it and takes a full bottle of suicide pills, much to Ian's disgust. However, the death is delayed since the pills take a while to kick in. Whilst waiting to die, Robbie tells the goth that Ian never saw The Wizard of Oz, prompting Ian to tell him to shut up again. The goth is shocked that Ian never saw The Wizard of Oz and he tells Ian that The Wizard of Oz is his favorite movie but he finally succumbs to the suicide pills.
Anthony walks into the house, asking who took a dump on the porch. Ian says he doesn't know and describes the day's events as "pretty sh***y" as they, including the goth who seemingly died, all laugh. Robbie brings back up the fact Ian never saw The Wizard of Oz, but Ian finally snaps and threatens to poop him out. The video concludes with the message saying that no tapeworms were harmed in the making of the video but Anthony's boobs were. People are then told to subscribe to the channel:
- "Thanks for subscribing guys! Whoa, whoa, I gotta burp! *Burp*"
- —Subscription Ending
- The concept for this video existed as early as 2008. In Smosh Sued for $20 Million (April Fools), Anthony was going to sell a notepad used for writing down video ideas, and included in such was a then-unused Magical Tapeworm idea.
- The "Magical Tapeworm" concept was also referenced in OUR VIDEO IDEAS STOLEN!
- The story of the Butt Serpents' animation is similar to that of The Legend of Zelda: The Wind Waker.
- No other actors besides Ian and Anthony appear in this video; Ian plays himself, the narrator, and the postman, while Anthony also plays himself, the Goth, and voices Robbie the Magical Tapeworm.
- The goth only says "magical tapeworm" once. He refers to it as either a "butt serpent" or "magic stapler".
- During the story of the Butt Serpent, the ancient drawings show that the magical tapeworms created McDonald's.
- Ironically, even tough the goth says his favorite movie is The Wizard of Oz, his castle is a picture of Hogwarts from the Harry Potter films. Furthermore, the goth looks like an accessorized version of Severus Snape from HARRY POTTER DELETED SCENES!