Colossus

The Colossus (also known as the Colossi and the Oni Titan) was a massive stone giant created by Lord Garmadon using his element to help conquer Ninjago. Shortly after Garmadon's battle with his son, he forged the Colossus from various massive rocks. It began wandering through Ninjago City, wreaking havoc and destroying builds before the Ninja intervened. In the ensuing chaos, the Colossus grabbed Destiny's Bounty and crushed it, leading Lloyd and the others to believe the original Ninja and Wu were dead.

For several weeks, Garmadon used the Colossus to maintain his oppressive hold on Ninjago City. The Colossus remained docile for a while, before Garmadon awakened it to chase Nya's armored car. The being nearly crushed the vehicle, though it escaped unscathed. After Skylor absorbed some of Garmadon's element, she was able to gain control of the Colossus; as she and Garmadon struggled for control, it stumbled and destroyed numerous buildings; in the process, an apartment was razed and Harumi was killed.

Enraged by Harumi's death, Garmadon unleashed the full wrath of the Colossus on the city. When the Ninja finally returned with several dragons, they fought against the Colossus. Kai tied numerous chains around it, incapacitating the being. After Lloyd caused Garmadon to lose his power, the being crumbled into lifeless rocks.

Big Trouble, Little Ninjago
Lord Garmadon and the Sons of Garmadon arrived at a village on their way to New Ninjago City. When a villager told them that their village would fight, Harumi told Garmadon that the Villagers did not know of his power. Garmadon they used his True Potential to form a mighty beast, the Colossus, causing the Village to yield to Emperor Garmadon.

The Colossus attacks New Ninjago City and Kai, Jay, Cole, Zane, and P.I.X.A.L. go to face it. They are surprised by its immense size and try to figure out how to destroy it. Cole cracks the ground, causing the Colossus to fall, but it just gets back up again. It holds onto some wires overhead, which Jay uses to electrocute it. It falls again, but gets back up again. It swipes at a building, knocking a room away, revealing a citizen on the toilet. The Ninja realize they cannot beat it the four of them board the Destiny's Bounty 2.0 to get Lloyd and escape. They find Lloyd and try to get him on board. He throws the toddler Wu to them, but the Oni TItan then grabs the Bounty and crushes it. Lloyd and Harumi believe that the Ninja and Wu were killed. In actuality, they survived, having been transported to another realm.

Firstbourne
As Garmadon watched over the city from his new throne, the Colossus was seen guarding it and after Harumi reported to Garmadon that Lloyd still hasn't been caught. Garmadon was posed to use Colossus to destroy half the city to draw him out, but Harumi quickly stopped him as that action was unnecessary and suggested sending Mr. E instead.

Iron & Stone
The Colossus stands inactive by Borg Tower while Garmadon executes Mr. E for his failure.

The Gilded Path
When Lloyd, Nya, Skylor and Dareth escape the Garbage Depot in their Armored Car, Garmadon activates the Colossus to catch them. It easily jumps in front of them. Nya begins to reverese the car, but the Colossus steps on it, starting to crush it with its foot. Lloyd pleads with his dad not to crush them, and for a second, Garmadon hesitates. He is then attacked by P.I.X.A.L., who he shoots from the sky. However, this gives Nya a chance to escape from the foot and drive away, the Colossus losing balance and falling down to the road.

The Weakest Link
The remaining Resistance members formulate a plan to take control of the Colossus and use it against Garmadon. Mistaké shapeshifts into a doppelgänger of Harumi, who they recently took prisoner. They plan for "Harumi" to take Skylor to Garmadon, and using her element, she'll absorb Garmadon's power and use it to take control of the Colossus. Their plan succeeds, with Skylor gaining the element - though Mistaké is killed by Garmadon.

Saving Faith
After Skylor touches Garmadon, she attempts to control the Colossus, but Garmadon instead uses it to walk towards them. Eventually, she takes control of it, using it to fling Ultra Violet across the city and defeat Killow. She then sends it up Borg Tower, prompting Harumi to flee, as Garmadon tries to retake control of his Colossus. It then smashes into the top of the tower, destroying Garmadon's throne.

Garmadon keeps trying to retake control, fighting mentally for command, though Skylor maintains her grip on the being. As Harumi flees into a nearby apartment, the Colossus stumbles into the building. Realizing her fate is sealed, Harumi stands on the building's roof as it collapses. Enraged by her demise, Garmadon unleashes the Colossus on Ninjago, and it begins causing even greater destruction.

Lessons for a Master
The Colossus approaches a nearby building, where Lloyd, Nya, Dareth and an unconscious Skylor stand on the rooftop. As they flee the rooftop, the Colossus begins thrusting debris at them, before they ultimately escape. Consumed by rage, Garmadon continues the Colossus's rampage, as it continues smashing buildings apart in search of Lloyd.

Green Destiny
After the original Ninja return to Ninjago, along with a group of dragons from the First Realm, they reunite with their allies and prepare for a final battle against Garmadon's forces. That night, the original Ninja and their dragons attack the Colossus. They fire their Vengestone Harpoons they gained from the Dragon Hunters, in a bid to incapacitate the Colossus.

Though the chains repeatedly hold the being, time and time again it breaks free and continues causing destruction. Eventually, Kai jumps onto the Colossus, and gets close enough to bind the chains together even tighter. With help from the people of Ninjago, as well as Wu and Firstbourne, he manages to make the chains tight enough that the Colossus stumbles and falls. After Lloyd uses the Art of the Silent Fist against his father, Lord Garmadon loses his element of destruction. Consequently, the Colossus loses all its strength; its body crumbles apart into lifeless rocks once more.

Season 8: Sons of Garmadon

 * 84. "Big Trouble, Little Ninjago"

Season 9: Hunted

 * 85. "Firstbourne"
 * 86. "Iron & Stone"
 * 87. "Radio Free Ninjago"
 * 89. "The Gilded Path"
 * 91. "The Weakest Link"
 * 92. "Saving Faith"
 * 93. "Lessons for a Master"
 * 94. "Green Destiny"