Mystery Mountain is a location first seen in the episode "Race Up Mystery Mountain". It is the former lair of Night Ninja and is also the home of both An Yu, as revealed in "Meet An Yu", and Munki-Gu.
Location and appearance
The exact nature of Mystery Mountain is inconsistent throughout the series. In Season 2, it was suggested to be located in another dimension or world, but as of Season 3 (and in some Season 2 episodes), it is frequently depicted as an island floating on a cloud above the city.
Mystery Mountain is, as its name suggests, a mountain. There is a single path with stairs that leads from the foot of the mountain to the top.
Mystery Mountain is surrounded by a bamboo forest. It contains a pagoda on top, a cave near the top, and various ornaments at the foot and along the path, all of which resemble ancient Japanese or Chinese architecture. The stairs leading up from the forest to Mystery Mountain are lit by lanterns.
Several booby traps are in place to protect the pagoda, including a coded lock on the door, dragon tongues and trapdoors.
Next to the mountain is a usually inactive volcano.
The mountain contains several sources of red Sticky Splat that can sometimes shoot up from the ground like geysers.
Mystery Mountain can only be accessed through one of two portals.
The first, and most frequently seen, portal is located in the city where the PJ Masks reside. To open the portal, one has to go to the wall the portal is hidden behind and use a ritual described in the Scroll of Mystery Mountain, an ancient scroll that was discovered in the vault of the Museum and promptly stolen by Night Ninja. The ritual originally involved multiple hand movements, ending with drawing the infinity symbol in the air. As of Season 3 (and a few Season 2 episodes), only drawing the symbol is enough to open the portal.
The second portal to Mystery Mountain can be opened in the air, as seen in "Flight of the Ninja" and "The Disappearing Ninjas". If one flies with just the right velocity, height, and perform the entrance ritual correctly, one will be able to travel to Mystery Mountain through a portal that's opened in the sky.
Mystery Mountain contains several relics of power, most of which are stored in the Pagoda on top of the mountain. So far these relics include:
In the Series
On their first visit to Mystery Mountain, "Race Up Mystery Mountain", the PJ Masks competed with Night Ninja to get the ring first, but both failed. Despite this, the former are lucky that the latter didn't get the ring. The second time, "The Mountain Prisoner", Night Ninja forced the PJ Masks to get the ring for him by taking PJ Robot prisoner. This time they succeeded and the PJs' prize was a freed PJ Robot, but discovered the ring had no powers at all. What the ring and the traps were truly about was teaching any potential finders the value of teamwork.
Although he failed to obtain the ring, and since the PJ Masks failed to retrieve the Mystery Mountain Scroll from him, Night Ninja made Mystery Mountain into his new lair after these events. The mountain was next seen in "Gekko Vs. the Splatcano", in which Night Ninja transformed the mountain into a Splatcano, forcing the PJ Masks to once again travel to the mountain and stop him.
In "Wolfy Mountain", the Wolfy Kids discovered Mystery Mountain and tried to take it from Night Ninja, forcing the villain to team up with the PJ Masks.
In "Flight of the Ninja", which was also the last appearance of Mystery Mountain in Season 2, Night Ninja plans to launch a giant Sticky Splat onto the museum.
In "Armadylan Zen", which is also the first appearance of Mystery Mountain in Season 3, the PJ Masks take Armadylan on a zen trip in Mystery Mountain to help him to calm down, since Armadylan gets easily angry by Night Ninja and his Ninjalinos throwing sticky splats at him.
In "Werejalinos", the Wolfy Kids and their new allies, the Werejalinos, tried to take Mystery Mountain from Night Ninja, but the Wolfies ended up trapped by the dragon tongues, and the PJ Masks convinced the Werejalinos to give up being werewolves.
In "The Secret of the Pagoda", the PJ Masks work together with An Yu to stop Night Ninja and his Ninjalinos from stealing the Golden Wand from the pagoda. The PJs even end up finally seeing the inside of the pagoda.
In "Storm of the Ninja", the PJ Masks have to help An Yu to solve an ancient riddle to stop Night Ninja from forming a storm with a staff that would help him get to the Pagoda.
In the short "An Yu's Bird Rescue", An Yu invites Owlette over to relax with her. During their meditation, they assist a baby bird in learning how to fly.
In the short "PJ Masks Surprise", the PJ Masks throw a surprise party for An Yu, who has not heard of the word "party". They were about to serve cake, but it gets devoured by one of the dragon statues, leaving both An Yu and the PJs stupefied for a few seconds before going straight to the dancing. This is the first time PJ Robot meets An Yu, as well as the first time since "The Mountain Prisoner" for the former to be at Mystery Mountain, although it's currently unknown when and how he properly met the latter.
In "The Splat Monster", the Teeny Weeny Ninjalino discovers the secret room filled with a special kind of sticky splat named Transforming Splat in the cave of Mystery Mountain.
In "Clash on Mystery Mountain", Armadylan went to take An Yu's staff from her, thinking that she was a villain at first, but realizes she wasn't actually a bad guy; he was only tricked by Night Ninja, who tried to take control of the mountain again.
In "A Teeny Weeny Problem", An Yu tries to train Teeny Weeny/the Splat Monster to be the Mystery Mountain's Guardian assistant.
In "Do The Gekko", Night Ninja stole one of the special bamboos, the same kind An Yu’s staff is made of, and filled it with Ninja Magic. An Yu wasn't able to stop the ninjas as they poof away, so she asks the PJ Masks for help, as well as discovering their daytime counterparts for the first time.
In "The Disappearing Ninjas", Romeo uses the Sky Factory to imprison the Ninjalinos to use their power to open the sky portal to Mystery Mountain, and ordered his Fly Bots to take everything from the Pagoda.
In "Gekko Everywhere", which was also the last appearance of An Yu in Season 3, she seems to have changed the locks on the pagoda's gate to keep Night Ninja out, as mentioned by the latter. So in order to get in, Night Ninja has built a catapult to launch himself and his Ninjalinos into the pagoda, but has forgotten about the booby traps, which he finally realizes when one of his Ninjalinos gets flung out of the outside of the pagoda. Gekko gets rid of the catapult later, causing Night Ninja to chase after it, and, halfway down, warns Catboy that he'll get his little green friend for that. Catboy meets up with Gekko and An Yu at the top of the mountain, where she thanks Gekko for his help and warns him about the Teleporting Crystal that he has in his hand.