Child's Play

"There comes a time when we all must grow up. When that time comes, it's important not to forget the lessons of our childhood. Because childhood is the greatest training ground one will ever have. Yes, the time before the final battle has grown shorter, but the Green Ninja has grown stronger." - Sensei Wu at the end of the episode.

Child's Play is the fifth episode in season two.

Plot
The episode begins with the Destiny's Bounty flying over the Jamanakai Village, with Lloyd lamenting that he must train and not play with others or enjoy his youth. Nya then tells the Ninja that Lord Garmadon has been spotted at the museum.

Once there, Lord Garmadon tells the Serpentine he is going to revive the extinct Grundle in another attempt to destroy the Ninja. As he is using the Mega Weapon, the Ninja watch and then burst in and interrupt the process.

Garmadon leaves in a fury, while the Serpentine Generals steal a sarcophagus for compensation. The Ninja chase after them, but fall behind. The Generals can't fit the sarcophagus through a manhole with them, they leave it behind and escape.

The Ninja then realize they have been turned into kids. When the police arrive on the scene, they accuse the Ninja of the theft and take them back to the museum to apologize for their actions. The museum director accepts their apologies, but questions where the Grundle fossil has disappeared to. The Ninja realize the Grundle must have been revived after all, and to escape the cops, the Ninja disguise themselves and run off with some school kids that are on a field trip. The Grundle appears on top of the museum, scaring a crowd of people in the surrounding area.

Sensei Wu and Nya, worried that the Ninja haven't returned yet, leave Lloyd behind to go search for them. As Lloyd is playing a videogame, he receives a call from Jay telling him to meet them at a pizza parlor and to bring their weapons. When they meet up, Kai informs Lloyd of the situation and the group wonders what they should do about the Grundle. Lloyd, knowing exactly who would be the most knowledgeable on the creature, brings them to a comic book store and introduces them to the sales clerk, Rufus Macallister. Rufus informs him that illuma-swords would work well, as the Grundle is nocturnal, but the shop only gives them out as a prize for winning a comic book trivia competition. Lloyd leaves a message for Sensei Wu and Nya back at the Destiny's Bounty, quickly telling them of what happened and their current location. Sensei Wu and Nya then go to Mystake for Tomorrow's Tea to turn the Ninja back into their older selves and the Grundle back into bones.

Meanwhile, Lloyd loses the competition and the Grundle shows up. The Ninja grab the illuma-swords to defend against the Grundle, but because they were meant as props they break easily. Lloyd attempts to take on the monster with his own powers but is quickly knocked aside. Just as the Grundel is about to consume the Ninja, Sensei Wu and Nya arrive with Tomorrow's Tea, tossing it to them and telling them to use it in order to age the creature back into bones, as well as themselves back into their normal states. The Ninja hesitate, realizing it would mean Lloyd growing older as well and missing out on his childhood. Lloyd, accepting the consequences, uses the tea to defeat the Grundle. The episode ends with the writer handing Lloyd a comic, which he says he has earned. Lloyd declines, saying he already knows how it ends. It is a comic where Lloyd is defensively fighting against his father under a classic comic book font-stylized title of "Green Ninja."

Trivia

 * The title is a reference to the horror movie, Child's Play.
 * Zane tells the others that "Nindroids don't dream" but he dreamed in the episode Never Trust a Snake
 * The Cover of the Green Ninja comic is possibly referencing Star Wars with Lloyd and his dad appear to be fighting with Light Sabers.
 * Just like Power Rangers, when the Ninjas aren't in their Ninja outfits, they wear their colors.
 * The glow sticks are also a reference to Star Wars.