Jake kills a fly that gets into his soup. However, he and Finn must get creative when the fly returns as a powerful ghost to haunt them.
- Artistic License – Medicine: Jake blames ghost flies for spreading "diseases, such as tuberculosis, polio, dysentery". Tuberculosis is primarily spread via aerosol transmission, while polio and dysentery are usually transmitted through contaminated food or water.
- Backhanded ApologyJake: I'm sorry you were born a fly and I had to kill you, you disgusting, disgusting creature.
- Bedsheet Ghost: The ghost fly looks like a fly in a bedsheet.
- Chekhov's Skill: At the beginning, BMO is practicing kung fu.
- Demonic Possession: Finn gets possessed by the ghost fly which turns him to a humanoid fly.
- Disney Death: To fight the ghost fly, Jake becomes a ghost by having BMO stop his heart. When he's back in his own body, he thinks BMO started his heart again, but it was really Doctor Princess.
- Epic Fail: Finn tries to make his protective circle bigger to reach his magazine, but somehow ends up drawing a woman instead.
- Flatline Plotline: Jake intentionally 'dies' temporarily by getting his heart stopped so that his ghost can fight the ghost fly.
- Fly in the Soup: This episode starts with this trope in action, only to take a sharp turn after the fly returns as a ghost after being killed.
- Hesitation Equals Dishonesty: When Jake wakes up in the hospital and assumes BMO restarted his heart as planned.BMO: Yes... Yay, BMO... BMO is so good...
- Orphaned Set Up: Jake starts to tell a joke to BMO without finishing it so his ghost will have unfinished business. We hear the set-up ("What do you call a bear that only attacks guys named Paul?"), but the episode ends before Jake gets around to telling BMO the punchline.one guess
- Our Ghosts Are Different:
- The ghost fly has a absurdly sharp scythe, telekinesis, and demonic possession.
- It appears that inanimate objects can become ghosts, but they can only be seen by other ghosts.
- Screw This, I'm Outta Here: Finn, Jake, and BMO call Peppermint Butler to help with their ghost fly problem. He draws protective circles around them, but the ghost fly takes his bag of magic from him before he can do more. Without his tools, Peppermint Butler jumps out of a window and leaves the trio on their own.
- Shout-Out: The shot of Peppermint Butler silhouetted on a hillside on his way to Finn and Jake's house is a parody of the poster to The Exorcist.
- Unfinished Business:
- The fly came back as a ghost because it never got a sip of Jake's soup. Once it has some ghost soup, it is able to rest in peace.
- To become a ghost, Jake tells a joke without finishing it before BMO stops his heart.
