Jay is only ninja to appear every episode due to the events of Season 6. Before that, Nya was the only one not to appear in every episode due to the events of the pilot.
In episode 2 In the US/Canadian version, Zane left a message in the fridge. However, in the variable language variation, he is actually sitting inside of the fridge when responding to Kai's reaction
In the rebooted series, the Nindroid's mask left eye has 3 laser pointed dots which is similar to the original 1987 predator's laser cannon having 3 laser pointed dots.
This series timeline is seperate from the film universe.
Character designs have been altered for the show's eight season in order to match up with the feature film. The film will not follow the storyline of the show, however it has been made for fans of the film to be able to start the show with its eighth season without the need to watch the previous seven.