Chief Mammatus is the current leader of the Keepers. Like the rest of the Keepers, Mammatus bore the responsibility granted by The First Spinjitzu Master of protecting the Storm Amulet, an ancient relic and the key to awakening Wojira. Deceived into thinking Wojira had awoken and was preparing to attack, Mammatus and the Keepers attempted to appease the beast, but to no avail. After apprehending the ninja, Mammatus planned to sacrifice Jay to the beast, but helped the ninja after they uncovered Ronin's falsification of Wojira. Following the battle, Mammatus realized the Storm Amulet was missing, but he and Nya quickly retook it from Clutch Powers.
Sometime later, the ninja face Kalmaar, who schemes to awaken Wojira. They return to Mammatus's island and explain the situation. Mammatus entrusts the ninja with protecting the Storm Amulet, but they quickly realize it's a fake, and the real one is in Clutch Powers' possession.
Prior to The Island
At some point, Mammatus became the leader of the Keepers, and was devoted to protecting the Storm Amulet. Prior to the ninja's arrival on the island, Ronin and the Kryptarium inmates created a ship intended to impersonate Wojira, fooling Mammatus and the Keepers into believing Wojira had returned. To appease what they believed was Wojira, they performed sacrifices. At first, they gave the criminals money, but then started to give them fruits and other materials until Mammatus realized that the Keepers needed to sacrifice someone to appease the fake Wojira forever.
Mammatus instructed the Keepers to capture the ninja, doing so successfully. When the ninja arrived at his throne room, he believed that the ninja were thieves seeking to steal the Storm Amulet. He explained the history of the Storm Amulet and their sacred oath about protecting it. Soon, he then declared the ninja prisoners.
After Mammatus told the ninja that they will forever be his prisoners, he told the Keepers to take the ninja away. But when Jay introduces himself, Mammatus tells the Keepers to take Jay somewhere else.
Later on, when the Keepers were done placing Jay on one of their boats, Mammatus makes a speech to the Keepers about Wojira and the First Spinjitzu Master, and that they will sacrifice Jay to Wojira so they can keep her submissive.
When Mammatus noticed that the ninja were freed from the poles, he and the other Keepers attempt to stop them from rescuing Jay, but failed to do so. After the ninja returned without Jay, he berated them for awakening Wojira. However, he then realized that Wojira was a fake, and explained the full history of how the Keepers gave tribute to a fraud. Wanting to redeem themselves, they gave a map of the coastline.
Mammatus greets the ninja and listens to what is happening. He tells the Keepers to prepare, but Nya says that they must take the Amulet away from the island. After being convinced, Mammatus hands Nya the amulet, bestowing the oath of protection, but Zane realizes it is a fake. He sees the ninja off as they depart.
Mammatus has purple-pink radiant skin like the other Keepers, orange eyes, and large yellow straw-like teeth with one golden tooth. The symbols on his face are golden, unlike other Keepers. As the lines on the side of his body on his minifigure suggest, he is overweight, probably due to enough food as a chief. It is unknown whether he has hair or is bald, although Clutch Powers drew him without hair. His body is covered with lavish golden armor with orange symbols, a dark orange image of Wojira on his belt, and many green glowing stones. His upper legs are also covered with armor and he has gold knee pads with green stones. He also wears a long vermilion cape and a large chief's crown made of gold on his head. Five green stones stick out of it, with another in the middle of the crown in front, round with the same symbol as on his throne. Two long white teeth are also stuck in the crown on the sides of the head.
Mammatus is committed to his duty to protect the Storm Amulet at all costs and is willing to use any means to protect it if it means success. He also seems to be relatively talkative, as he has explained everything about the amulet to the ninja, even though they just wanted to know which amulet he was referring to. He became a little more friendly when the ninja found out that Wojira was fake. He was even willing to hand over the amulet to Nya because he trusted her.
Weapons and abilities
- Storm: Like the other Keepers, Mammatus can create, generate, increase, absorb, conduct, shape, and manipulate electricity from his staff or the electrical storms from the storm belt, letting him redirect natural lightning in an electrical storm and use it to electrocute opponents.
- Lightning staff: As chief of the Keepers, Mammatus can handle his staff well, which he can blow up spinning and catch it again. However, he does not seem to be a very well-trained warrior, as although he was in a fighting position, the ninja easily defeated him and threw him to the ground.
As chief of the Keepers, Mammatus has power over his people and rules over them.
Although Mammatus had never seen Wojira alive, his ancestors were given the task by the First Spinjitzu Master to guard the Storm Amulet so that she could never wake up again. Mammatus continued in the role of his ancestors, and he had great respect and fear of Wojira. When she seemed to wake up, he sacrificed many of the things the Keepers had, including gold, wood, fruit, chicken, and man. He did all this to calm the Sleeper's anger and drive her back to sleep.
When the ninja first reached the Island of the Keepers, they were noticed by the Stone Guardians and captured by the Keepers. Mammatus then imprisoned them, but when he noticed Jay, he immediately picked him, choosing him as the human sacrifice that would appeased Wojira forever. He was angrily angry when the ninja managed to escape, so he tied them to a totem pole on the beach so they could watch their friend's sacrifice. However, when he learned from the ninja that Wojira was a fake, he told them where something so big could be hidden and helped them. When Ronin and his allies were imprisoned, he thanked the ninjas and let them go. Later, when they returned to the island, he welcomed them as his friends and was willing to hand over the amulet to them when he found that he was no longer safe.
Although Ronin never directly interacted with Mammatus, he was responsible for creating the fake Wojira and instilling in Mammatus the idea of sacrificing their valuables to her. When the ninja and Twitchy Tim defeated Ronin, Mammatus imprisoned him in their prison until he escaped or was released.
Mammatus is the latest in a long line of island leaders sworn to protect the Storm Amulet. This powerful artifact was given to his ancestors by the First Spinjitzu Master before Ninjago Island even existed. Like all Keepers of the Amulet, he tries to look tough as possible to outsiders!
Chief Mammatus is the head of the islanders! This high office is handed down in his family. If the Storm Amulet disappears from his island, it could end badly for his keepers - and for himself!
- LEGO Brawls (non-canon)
Behind the scenes
- He shares his name with a type of cloud.
- He is the tenth character to have a cape in the sets, the first eight are Lloyd (in his child version), Chen, Morro, the Time Twins, Harumi, Wu, the Blizzard Sword Masters, and Akita.
- He is the only Keeper that has an exclusive torso, legs and head on his minifigure.
- His name is never said in the show.
- There are some differences between his minifigure and his appearance in the show.
- While there are lines on the sides of his body showing his breasts and abdomen on his minifigure, they are missing in the show. Also, the collarbone is not visible in the show, which is covered by armor, which is located higher than in the sets.
- His cape has patterns on the bottom that are missing in the sets.
- In a drawing by Clutch Powers in "Riddle of the Sphinx," Mammatus gives away his crown, and he is seen to be bald. However, this could just be Clutch's interpretation of him.
- He doesn't like brushing his teeth.
- He has a gold tooth.
- He is referred to as "King Mammatus" in Jailbreak! and Jungle Warrior!.