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 start attacking Townsville.
Custody Battle contains examples of:
- Big "SHUT UP!": Brick gives one to both Mojo and HIM when the boys finally have 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 was disgusted that HIM would hypnotize scientists into sending the Earth into the Sun, which would reduce all of them to nothing. Fortunately, HIM quickly undid 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 scientist 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 hearth 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.
- Lost Voice Plot: Bubbles gets stuck 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.