What's the Big Idea?
Season 6, Episode 13b (136)
Episode name pun on: Mojo's idea to make the Girls bigger and the expression of the same name.
Screen image 322972
Airdate: August 27, 2004
Director: John McIntyre
Story: Paul Stec
Writer(s): Ken Allen
See also
"Roughing It Up"
"The Powerpuff Girls Rule!"

"What's the Big Idea?" is the twenty-third episode in the sixth season of The Powerpuff Girls. It is the one hundred and thirty-sixth episode overall. It is also the thirteenth episode along with "Roughing It Up". It is the second to final episode of the original series, followed by The Powerpuff Girls Rule!


Mojo Jojo makes the girls giants so that they can’t stop his crimes without causing massive collateral damage and it’s up to the Professor to save the day.


That day, Mojo Jojo was making a scale model of Townsville in 1:87th scale in his volcano observtory. Then, while he was thinking what to do, he put his figure in front of the Jewel shop. He thinks of another plan and took the figure to the Art Museum. However, he was spiked by the tower and jumped on the electric poles. Then the poles wrapped around him and destroyed his scale model. He then has the perfect idea for the Powerpuff Girls.

The Powerpuff Girls were oblivious about Mojo's plans. They were playing near his volcano. When they started arguing, Mojo walked between them. The Girls asked "What's the Big Idea?." Mojo replied "Exactly." He showed his newest creation, along with it's introduction etc., etc. He used it to make the Powerpuff Girls gigantically huge. At this gigantic size, they stepped on the electric poles, destroy buildings, and cause more chaos. The citizens tell them they are making things worse. Bubbles cried, causing huge tears. Then, they went to their home, flying but cause fires in Townsville.

While they went to Prof. Utonium, Mojo was stealing DVD's, jewels and money. Professor tried to repair the device while the Powerpuff Girls search for Mojo Jojo. The Professor finished the device and shrinks the girls back to normal size. After kicks and Punches, Mojo goes to jail as usual. He then tries to think how the girls got smaller as the device does not work that way. The narrator shows that Townsville actually got bigger than the planet Earth and the girls didn't get small. Narrator shows how the episode ends as "The day is saved by Powerpuff Girls + Don't Step on me!"


Major Characters

Minor Characters

  • Don Shank (animated)


Bubbles: [tears shed out] We just want to help.
[Starts to sob, tears drips]
People of Townsville: Ahh! Run away! Run away! 
[A big splash crashes]
Blossom: Bubbles, careful! I mean, seriously!
Bubbles: Sorry!
[Dries tear off, an eyelash crashes on car] 


  • This is the last 11-minute episode in production, though this is not the last-aired episode, which aired on March 25, 2005.
  • This episode is similar to every episode of the show with growth.
    • Pinky and the Brain: Tokyo Grows
    • Make Way for Noddy: Clockwork Mouse's Wish
    • Timbuctoo: Squeak has a Big Day Out
  • This was the last episode where Mojo was the main villain until "The Powerpuff Girls Rule!
  • This is the last episode of The Powerpuff Girls before making a special episode, "The Powerpuff Girls Rule!"
  • Bubbles' eye lashes can be seen making it the second or third time in general since the girls' lashes have been shown onscreen, first being The Rowdyruff Boys (episode) and the second being A Made Up Story.
  • Running gag: Characters ending their sentences with et cetera (etc).
  • It was the last episode to air in 2004, due to Canadian TV Series Atomic Betty premiering weeks later on Cartoon Network. It premiered on Canadian Soil on Teletoon on 6 September 2004.