Bonezai is a warrior in the Skulkin army. Long ago, Bonezai was banished to the Underworld, where he became a part of the Skulkin army and assisted his master, Samukai. Bonezai later became the vehicle designer for the Skulkin. His mechanical expertise is only eclipsed by his protection for his creations, as even slightly damaging one of his vehicles is an excellent way to distract and enrage him. Bonezai aided the Skulkin in their quest to stop the ninja from claiming the Golden Weapons.
The Skulkin managed to claim the weapons, though Samukai's attempt to keep the weapons from Lord Garmadon resulted in his demise. Afterward, Bonezai would remain in the Underworld with the other Skulkin, while Garmadon escaped into Ninjago to cause chaos. Bonezai and the Skulkin later helped Garmadon fight the Serpentine, who were trying to claim the Fangblades.
NOTE: To fill out the Skulkin ranks in the television series, most of the skeleton characters were used multiple times in group shots. As such, any notable appearances of an Ice Skeleton will be categorized here, for convenience.
A member of the Skulkin, Bonezai became their engineer for about five thousand years and went on to create their more infamous vehicles such as the Skull Truck and Turbo Shredder. At one point, Bonezai designed the Skull Motorbike, only for Chopov to redesign it to its current version, much to his dismay.
The entire Skulkin force then rallied behind Samukai and ambushed the ninja outside the cave holding the Scythe. While they quickly overpowered the ninja, Jay quickly figured out the key to Spinjitzu, thus turning the tide. Rocky then appeared and Samukai called a retreat.
On the way back to the Underworld, an Ice Skulkin piloted a Skull Motorbike while two others rode on the Skull Truck. Though the one on the bike was successful in returning home, the two on the Skull Truck were thrown off by Jay and Zane when they boarded the vehicle.
Bonezai, alongside his fellow Skulkin, surrounded Lord Garmadon as he cursed his brother over his exile. He proceeded to witness Samukai's clash and subsequent defeat, resulting in Garmadon's takeover of the Underworld.
Bonezai, alongside Wyplash, Chopov, and Krazi, ambushed Nya at the Four Weapons Blacksmith. However, the four of them were easily defeated, resulting in all of them being disassembled into several piles of bones.
Bonezai regrouped at the Fire Temple's entrance to the Under World alongside his fellow Skulkin under the command of Wyplash and attacked Kai when the latter stumbled upon them. However, he was sent fleeing back into the Under World by an attack from Flame, which subsequently sealed the entrance.
Bonezai is incredibly gifted when it comes to creating vehicles, alongside Dr. Julien as the engineers of the Skulkin. Despite being a member of the Skulkin, however, Bonezai is generally mild-mannered and less aggressive than his fellow soldiers. However, he also takes damage towards his creations very personally, going so far as to convert a fellow Skulkin into a tool rack just for putting a single scratch on the Turbo Shredder. His protectiveness and prioritizing of his vehicles is ultimately his greatest weakness, as damaging them can cost him valuable focus in battle. He is also prone to jealousy, being dismayed when Samukai favored Chopov's version of the Skull Motorbike over his own.
Bonezai's main distinguishing feature are red eyes which face in opposite directions, giving him a dimwitted look. His belt and armor are primarily white in color.
His favorite weapon is a Golden Pick Axe. He also carries an axe and a flail.
- He is considered the warrior of Ice in promotional material and the Ninjago Spinners game, but this is non-canon, as the Skulkin do not have Elemental Powers in the TV series.
- Bonezai test-drives his vehicles, usually at high speeds.
- He can be easily distracted in a fight by doing damage to one of his vehicles.
- He is the only skeleton warrior who doesn't have a hat.
- Bonezai's name is a combination of the words "bone" and "banzai."
- "Banzai" is a Japanese battle cry.
- In a Ninjago sticker book[ Which one? ], Bonezai and Chopov had their names switched.
- In LEGO Battles: Ninjago, Bonezai's appearance is used for the Skulkin's builder units. He also shows up as generic Skulkin followers in some of the Skulkin character's upgraded forms.
- In "Infamous", Bonezai's appearance is used as the basis for a Skulkin costume in a TV commercial starring the ninja, with the addition of a skullcap similar to Wu's first seen in "The Day Ninjago Stood Still".
- The only set to include his shoulder armor was his spinner set, to match the other Skulkin spinners by including armor and no headgear. Bonezai's appearance in the show uses this armor, making the show accurate Bonzai relatively uncommon.