After a trip to Aquatraz Water Park, Lisa becomes determined to set free Springfield's most vicious animals in captivity; Homer fulfills a lifelong dream of buying a boat, and quickly realizes boat ownership sucks.
Examples:
- Chekhov's Gun: One of the five signs Lolo knows is "Seinfeld." Lisa is able to convince the gorilla to trust her by turning the series on.
- Continuity Nod: Carl's and Lenny's respective sisters from "The Blue and the Gray" (known to casually date, respectively, Lenny and Carl) reappear.
- Didn't Think This Through: Bart frees a gorilla from the zoo to chase the high of altruism. Unfortunately, unlike the whale who had an ocean to swim in, a gorilla set loose will run wild into the city before being killed.
- Distinction Without a Difference: Jane Goodall rechristens the freed Lolo with what she sees as a name "worthy of such a magnificent creature": Popo.
- Expy Coexistence: Jane Goodall guest stars As Herself, and she's given a near-similar (if not the same) design as her (decididely not as good) stand-in Dr. Joan Bushwell from "Simpson Safari".
- Good Feels Good: After helping Lisa free an orca from the water park, Bart likes the feeling she describes for him as "altruism" and plans to free another captive animal. Downplayed in that, being Bart, he seems to unknowingly be actually compelled by his usual love for chaos.Bart: Altruism rocks! Like when you let something go and it smashes everything. Next, I want to altruism a rhino. Then I'm gonna altruism a robot with sledgehammers for hands. Sometimes I just want to sit back and watch the whole world altruism.
- Killer Gorilla: Lolo goes on an Escaped Animal Rampage after being freed by Bart.
- Stop Drowning and Stand Up: When Wiggum ends up in the ocean he says he can swim to shore, before deciding it's too much work. Then he realizes he can just stand and walk, but decides that's too much work as well.
