He is voiced by Paul Dobson.
General Kozu is the leader of the Stone Army and second-in-command to Lord Garmadon. He and the Stone Army were brought to life when venom from the Great Devourer spilled into the chamber they were being kept in. He was a translator for Lord Garmadon, because the rest of the Stone Army spoke in an unintelligible language. He was in charge of mining for the Dark Matter that would be used to create Garmadon's new ultimate weapon.
When the ninja were discovered on the island, Kozu and the Stone Army gave chase in several of their vehicles, following them to the Temple of Light where, upon seeing his warriors defeated by the newly charged-up ninja, he began to have misgivings. When he saw the Green Ninja, he retreated. When Garmadon heard of this, he ordered an immediate raise in defenses. Also, he wanted them to work on his new secret weapon. When the ninja stole Lord Garmadon's helmet that could control the Stone Warriors, General Kozu tried to chase them but wasn't fast enough. Later, when The Overlord wanted General Kozu to fire the Garmatron at Ninjago, he was attacked by Sensei Wu, and pushed into the cannon, where he was fired into "Grand Sensei Dareth's Mojo Dojo". Dareth told his students to attack Kozu, and they all pile on top of him. Later, in the Final Battle, he is pushed off of a building, and perished.
Then, in the Ninjago special "Day of the Departed", his spirit, as well as the spirits of other past villains, was released, and possessed mannequins of themselves in the museum. When Sensei Yang tells the villains choose a ninja to attack, Kozu chooses Dareth to get revenge. He finds some other Stone Warriors in the hall of sidekicks. After finding Dareth, Kozu chases him until they get to a storage room, where Dareth finds the Helmet of Shadows, which can control the Stone Warriors. He puts it on, and command the Stone Warriors to destroy Kozu again. Kozu is destroyed, and sent back to the Dearted Realm.