Liv Amara releases a swarm of adorable creatures called Mayoi into the city, but they're not as harmless as they appear.
- Artistic License Biology: Karmi first identifies the Mayoi as fungi, then claims they are part plant, part animal. Fungi are actually neither plants nor animals.
- All Animals Are Dogs: The medium-sized Mayoi basically act like a Big, Friendly Dog, showing behaviours like tail-wagging and playing fetch. Their original, cute forms act more like kittens, whereas their final, giant forms act bear-like.
- Box-and-Stick Trap: Big Hero 6 use one to try and trap a Mayoi.
- Comically Missing the Point: Krei is annoyed that Amara is getting all the attention at the Q&A, even though Hiro is unsubtly making accusations towards Amara.Amara: Okay, since you're an intern at Krei-Tech, I have some questions for you, Hiro—
Krei: Yeah, why aren't you asking me questions, intern?!
- Cuteness Proximity: The Mayoi are so adorable even stoic hardasses like GoGo and Granville coo like little girls in their presence.
- False Flag Operation: Liv gets Mr. Sparkles to claim responsibility for the monster attacks while she helps to foil him, thereby throwing any suspicion off herself. Big Hero 6 doesn't buy it for a moment, but the rest of the public does.
- Finish Dialogue in Unison: Hiro is able to accurately predict how Liv will finish a response in the Q&A session, because roughly 90% of her public statements are meaningless platitudes.
- Heroism Addict: Hiro publically asks Liv what exactly her company does and why monsters seem to show up wherever she goes, and her company seems to benefit from them. In response, she creates the mayoi who wreak havoc in the city. She also creates a serum which can change the Mayoi back to their tiny, cute forms and helps Big Hero 6 defeat them, reinforcing her good publicity while Mr. Sparkles, who is controlling them, takes credit for all the monster attacks.
- Immediate Self-Contradiction: Wasabi insists he won't be taken in by the Mayoi's cuteness, only to fall for the one the others managed to catch mere seconds later.
- Internal Reveal: Hiro suspects Liv is behind the recent monster attacks. The rest of Big Hero 6 agrees with him after the events of the episode.
- Miracle-Gro Monster: The Mayoi start out cute and fluffy, but when exposed to sunlight and food, they become...still cute cute and fluffy, but much bigger.
- Monster Protection Racket: Liv Amara creates the Mayoi that grow to giant size and wreck the city, then shows up with a serum that turns them back to their small and cute forms. This way she can present herself as a hero while Mr. Sparkles takes credits for all the monsters.
- Non-Malicious Monster: The Mayoi display no real aggression and are very friendly in their natural state, even when they grow to large sizes, allowing Big Hero 6 to easily herd them. Unfortunately, this only lasts until Mr. Sparkles takes direct control of them.
- People Jars: In the stinger, Amara goes into a containment room, where there's a stasis pod with what appears to be a young woman inside.
- Planimal: The Mayoi are plant-based creatures that can grow through photosynthesis as well as through consuming food.
- Pokémon Speak: The Mayoi only say "mayoi", which is why the people of San Fransokyo call them that.
- Shout-Out: The Mayoi, with their Planimal appearance, Pokémon Speak and three different forms (tiny cute ones, human-sized ones and giant monstrous ones) resemble a grass-type Pokémon.
- Stock Sound Effects: The roar of the giant Mayoi is the same stock monster roar used multiple times for Monster!Orso Knox.
- Teeth-Clenched Teamwork: Hiro very reluctantly accepts Liv's help in dealing with the Mayoi, since she's the only viable option at the moment.
- Villainous Rescue: Just when Big Hero 6 get cornered by the Mayoi, Amara comes in with her serum and helps turn them back into their normal forms, playing hero and throwing blame for the attacks on Mr. Sparkles.