During an excavation, Finn, Jake and Susan encounter a mysterious stranger who may hold the key to the past.
Tropes:
- The Bus Came Back: Tiffany returns after being eaten by a worm in "Dentist".
- Call-Back:
- Visual example. The Hyoomans from "Susan Strong" looked like humans but turned out to be Fish People beneath their hats. Dr. Gross looks like a fish person but turns out to be a human wearing a suit. Well, human+.
- One of the animals Dr. Gross had is a Clock-Bear, the same one first shown in Finn's dream from "Hoots".
- Department of Redundancy Department: Tiffany brags that the wolf-lards have the high endurance of a sea lard combined with the bloodthirsty killer instincts… of a sea lard.
- EmPHAsis On The Wrong SylLAble: Dr. Gross's song contains so many weird emphases that it's definitely meant to say something about her character.
- Evilutionary Biologist: Dr. Gross believes that natural evolution is too slow, so she goes around making Mix-and-Match Critters and Cyborgs out of innocent creatures against their will. Susan turns out to be one of her experiments gone rogue.
- Mix-and-Match Critters: Dr. Gross's ship is full of weird hybrid creatures, such as a half-scorpion, half-chipmunk "scorp-munk" or a pack of wolf-lards.
- Slipping a Mickey: Dr. Gross gives Finn, Jake and Susan lollipops filled with a paralyzing agent so she can experiment on them. Susan hides hers under her chin so she can rescue Finn and Jake.
- There Is Another:
- Dr. Gross turns out to be a human (well, a cyborg, or "human+" as she calls it) and reveals that she was kicked out of an island inhabited by humans for her Mad Scientist tendencies.
- Finn lampshades how he's not the Last of His Kind anymore, bringing up his father, Betty, and (occasionally) Ice King. Granted, Martin has now ascended into a different plane of existence so he's pretty much gone, Betty is a Fish out of Temporal Water, and Simon was transformed into a knockoff of... whatever Urgence Evergreen was so he doesn't count as long as he's the Ice King.
- Transhuman: Dr. Gross is this, being a human with many cybernetic enhancements. She plans on doing this to Finn, Jake, and Susan, whether they want to or not.
- Wham Line: Dr. Gross ends up revealing that Susan has some implants by complete accident.Dr. Gross: Oh, you already got an implant. It looks deactivated, though… (observes it closer( Wait… X-J-7-7. Wait! You're one of—- (Susan punches her in the face)
- You Monster!: Finn refuses to cooperate with Dr. Gross"We'll never work for you, you monster!"
