Custody Battle: When Mojo Jojo finds out the Rowdyruff Boys are back, but that HIM is now their father, he challenges his rival to a competition to see who is more evil.
The City of Nutsville: Bubbles gets stung in the throat just as a bunch of squirrels starts attacking Townsville.
Custody Battle contains examples of:
- Big "SHUT UP!": The boys give one to both Mojo and HIM when they've finally had enough of their bickering.
- Continuity Nod: several events from previous episodes starring the Rowdyruff boys are referenced, including their original creation by Mojo way back in season 1 and HIM bringing them back.
- Even Evil Has Standards: Mojo is disgusted that HIM would hypnotize scientists into sending the Earth into the Sun, which would reduce all of them to nothing. Fortunately, HIM quickly undoes it with a flick of his wrist.
- Evil vs. Evil: Mojo Jojo vs HIM.
- Humongous Mecha: Mojo gives one to the boys in an attempt to win them over.
- Mind-Control Device: HIM uses a magic pan flute to get a group of scientists to activate a secret weapon that will launch Earth into the sun.
- Naked People Are Funny: the mayor ends up nude again when he crawls through a fence and his clothes are torn off.
- Taking the Kids: Mojo and HIM both try to prove themselves the more evil (and thus better) father for the boys.
- Villain Episode: Mojo Jojo, HIM, and the Rowdyruff Boys are the focus of this episode, with the Powerpuff Girls only appearing in flashbacks. Even the typical heart-shaped ending is different to reflect this.
The City of Nutsville contains examples of:
- The Bus Came Back: Bullet, the super-powered squirrel from Stray Bullet, makes a return appearance in this episode.
- Irony: For once Bubbles squirrel speak is actually needed, and now she cant use it. Buttercup even lampshades the irony of the situation.
- Laser-Guided Karma: For laughing at Bubbles, Blossom and Buttercup have to clean up the remains of the Mayor's statue that got destroyed.
- Lost Voice Plot: Bubbles gets stung by a bee inside her throat, and loses the ability to talk properly.
- This Looks Like a Job for Aquaman: For once the girls are faced with a situation where Bubbles unique power of being able to talk to squirrels would really be useful. Unfortunately, she cant do it because of the bee sting earlier.
- Zerg Rush: All the squirrels swarming the city.