"Muira-Horror!" is the thirty-second episode of Big Hero 6: The Series. It premiered on May 14, 2019 and is the seventh episode in the second season.
When Hiro and Go Go accompany Krei to the woods to deal with Nedd Ludd, they run into the monster of legend, the Hibagon.
Hiro accompanies Alistair Krei on a trip to Muirahara Woods, the latter planning to buy the forest to build a tech campus for Krei Tech. At the same time, they run into Liv Amara, accompanied by Chris, as Sycorax intends to buy the land for a nature conservatory. Krei and Amara try to bid each other out, but both are unable to get reception on their phones. Hiro explains this is due to a meteorite named Bessie interfering with electronics and is guarded by Ned Ludd. Krei recognizes Ned as an old golfing partner and sets out to convince to take Bessie and leave, with Hiro tagging along due to his contract. Meanwhile, Amara hatches a plot to acquire Bessie by using Ned to take out Krei.
Meanwhile, at the Lucky Cat Café, Go Go opts to accompany Hiro and Krei to Muirahara since she has the wilderness experience. On that note, Honey Lemon, Wasabi, Fred, Baymax, and Mini-Max volunteer to watch the café while Aunt Cass attends to a catering event that day. In the woods, at Ned's treehouse, Ned is accosted by Amara before he is ambushed and incapacitated by Chris. Amara then places a transdermal patch on the unconscious Ned.
Hiro, Go Go and Krei enter the woods in a van that soon gives out when it comes in the range of Bessie's magnetic field. Meanwhile, back at the café, Baymax and Mini-Max greet customers as Honey and Wasabi help serve food, and Fred keeps eating the orders himself. However, Mochi runs outside into the streets once he spots the door open, prompting Fred, Baymax, and Mini-Max to go looking for the cat.
Hiro, Go Go, and Krei continue the trek on foot and soon run into Ned. Meanwhile, Amara has Chris place Bessie into a containment unit. The unit nullifies the meteorite's influence, including on Ned's patch, which Amara activates. This mutates Ned into a monster—a genuine Hibagon—in front of Hiro, Go Go, and Krei. The Hibagon pursues the trio through the wood. Go Go falls into a stream towards a waterfall, but she is saved with a branch from Krei. Krei has him and Hiro coat themselves in mud to avoid the creature's scent. Go Go is reluctant before the Hibagon reappears and chases after her. The Hibagon grabs her until Hiro swats it back with a tree trunk, causing it to throw Go Go and leaving her with an injured leg.
Back at Muirahara, Krei fashions a makeshift brace for Go Go to walk in. When Hiro asks how he could know such survival skills, Krei admits that he camped as a child and spent time in the woods without any friends. Just as the trio realize their phones are receptive again, the Hibagon closes back in on them; Krei apparently abandons Hiro and Go Go to the beast but arrives moments later with the van (which reactivated when Bessie was contained) and saves Hiro and Go Go. The trio drives out of the forest, but the Hibagon follows them on a moving truck.
Meanwhile, Fred, Baymax, and Mini-Max take the search for Mochi in the skies. As they fly over San Fransokyo Bridge, they spot Hiro, Go Go, and Krei driving back with the Hibagon nearby. The Hibagon then jumps on the van. Krei abruptly stops the van which throws the Hibagon off and causes a traffic jam. Fred, Baymax, and Mini-Max arrive to confront the Hibagon, but the Hibagon throws both Mini-Max and Fred over the bridge (though Mini-Max manages to save them both) and takes out Baymax by redirecting his rocket fist back at the robot. Before the Hibagon can strike Hiro, Go Go, and Krei, Mochi springs on the Hibagon, scratching him numerous times until he knocks off Amara's patch and reverts him back to Ned. After the battle, Hiro apologizes to Krei for misjudging him and Krei decides not to tear down the woods.
While Fred return to the café with a drained Baymax and Mini-Max, Hiro and Go Go give Ned a ride back to his treehouse. Noticing that the van was functioning, Ned worriedly goes to check on Bessie. Hiro and Go Go examine the patch that was on Ned before they are alerted by Ned that Bessie is gone. Back at Sycorax, Amara's experiments on Bessie break the meteorite and reveals a raw mass of energy. Amara states that once she is done with Bessie, Bessie will be "beautiful".
- Fred is the only human to wear his armor like in Mini-Max
- Ned Ludd's shoes are destroyed when he transforms into the Hibagon. After he changes back, they are somehow restored on his feet.