Finn and Jake's parents hunt an unearthly menace in the woods.
Tropes:
- Bait-and-Switch: Near the end, Margaret goes into labor the same time Joshua's giant head welt is about to burst. We then see Jake lying on the floor—zoom out to show Margaret who is still pregnant. It turns out Margaret was pregnant with Jermaine and Jake came from the welt.
- Birthday Episode: It's Jake's birthday and Finn and BMO want him to tell a story about how he was born, setting up the flashback.
- Body Horror: Poisoned by the alien beast, Joshua is in great pain. He grows veins all over his body and a big blue welt starts pulsating from his head.
- Brainy Baby: Seconds after birth, Jake is able to sing and tap dance before passing out.
- Call-Forward:
- Joshua reads from a ticker tape about a vampire girl in the grasslands (Marceline) and a small fire goblin burning down the Candy Kingdom's forests (Flame Princess).
- During the scene with Tree Trunks, her then-husband Wyatt the manatee from "Apple Wedding" makes an appearance.
- When Jake was born, he landed in a small puddle of mud, which is how Jake thought he got his powers in "The Witch's Garden".
- Chekhov's Boomerang: Jake's brother Jermaine finally comes up again after only being briefly mentioned a few times since "Crystals Have Power".
- Face Full of Alien Wing-Wong: The bite that Joshua gets from the alien turns into a welt that eventually spawns Jake.
- Foreshadowing: The alien is a stretchy shapeshifter, like Jake.
- Framing Device: Played with. The Whole Episode Flashback is apparently Jake telling a story about his parents...except the end of the episode suggests that Jake hasn't been telling the story seen on-screen at all.
- Freeze-Frame Bonus: If you pause, you can read most of the book of venom and antidotes
◊. - Let Us Never Speak of This Again: Joshua and Margaret agree to never tell anyone about how Jake was born, not even Jake. The end of the flashback shows that even though the audience saw this in a flashback where Jake's story is the Framing Device, he still doesn't know.
- Lock-and-Load Montage: Margaret is seen heavily gearing up to chase down the monster that bit her husband so she can get a venom sample.
- Mister Seahorse: This episode reveals that Joshua was the one who gave birth to Jake, after being bitten on the head by a shapeshifting alien and Jake later popping out of the resulting wound.
- Non-Human Humanoid Hybrid: The origin of Jake's powers is that he's a anthropomorphic dog/alien hybrid.
- Pregnant Badass: Margaret, despite being heavily pregnant, is still a top notch detective and adventurer. When Joshua is poisoned, she heads out to extract venom from the beast who bit him to make an antidote.
- "Scooby-Doo" Hoax: The "monster" stealing Tree Trunks' pies turns out to be her husband Wyatt.
- Shout-Out: Jake doing a brief song-and-dance after exploding from his father's boil is similar to the Alien parody sequence in Spaceballs.
- Wham Episode: This episode introduces a shocking twist into the origin of Jake's powers: he's a half-dog half-alien hybrid birthed from a growth on his father's head!
- Whole Episode Flashback: Rationally, since this one stars a couple of Posthumous Characters.
- Would Hurt a Child: Even after the alien shape-shifter runs with Margaret's assumption that it's a baby in order to avoid getting attacked anymore, Margaret still KO's it to get its venom while saying "Imsorryimsorryimsorryimsorry".
