The film was first hinted at in a bonus feature on The LEGO Movie (2014) Blu-ray, called "Enter the Ninjago." In the short, an executive changes several scenes in The LEGO Movie to feature Lloyd, because "kids love ninjas." Emmet suggests that instead of changing the film to add a ninja, they just make a movie about ninjas, which the executive claims is a great idea. The rest of the short becomes a trailer for this untitled movie, which they claim would go on to be a major bomb at the box-office.
When Lloyd and Garmadon are captured by all of Garmadon's fired general number ones and about to be thrown into a volcano, one says the lava in it is 15 million degress Kelvin. This translates to nearly 27 million degrees Fahrenheit, as hot as the center of the sun.