When Aquaman is reported missing, the Titans think that Black Manta must be responsible, and end up caught in his trap.
Tropes:
- Big Damn Heroes: Just when Black Manta decides to just get rid of the Titans and Aquaman permanently instead of keeping them trapped, Robin (who had been transformed into a fish by Aquaman and then flushed down the drain by Black Manta after their escape plan failed) suddenly breaks through the floor riding atop a whale he tamed and knocks the villain out.
- Dirty Coward: When Black Manta's cat attacks the Titans in the aquarium, they go to Aquaman for help. Aquaman then claims that he's allergic to cats and goes and hides inside the aquarium's mini castle.
- Glad I Thought of It: Whenever Robin suggests a plan in order to break out of the aquarium, Aquaman calls it stupid, then suggests the exact same plan while striking more dramatic poses and forces Robin into the most dangerous/embarrassing part of it. The other Titans are thoroughly convinced of Aquaman's awesomeness, up until Black Manta flushes Robin down the drain and Aquaman panics when having to come up with his own plan, at which point they realize his uselessness.
- Interspecies Romance: Beast Boy transforms into a seahorse in order to communicate with Aquaman's current steed, Storm's second cousin Light Breeze. Light Breeze ends up smitten and convinces Beast Boy to carry her babies. And he does.
- Mister Seahorse: A very literal version, as Beast Boy ends up carrying Light Breeze's babies while transformed into a seahorse, and claims that his water broke at the episode's end.
- Shrink Ray: One of these is used by Black Manta in order to shrink the Titans (and, as it turns out, Aquaman) and trap them in his aquarium.
- Whole-Plot Reference: The episode's title, plus its plot of a group trying to escape from an aquarium by clogging up the filter, is a reference to Finding Nemo.
