|Episode name pun on: Monstrocity|
|Airdate:||September 5, 2003|
|Story:|| Dave Dunnett|
Amy Keating Rogers
|Writer(s):|| Carey Yost|
"Shut the Pup Up"
Monstra-City is the first episode of Season 5.
When the Mayor of Townsville finds the deed to Monster Isle, the Monsters move to Townsville causing havoc between monsters and humans. The Powerpuff Girls try to keep the peace and let everyone in Townsville live in harmony. But when Townsville gets way too crowded, they trick the Mayor into giving back Monster Isle to all of the monsters with the help of a monster lawyer.
- This is the one of the episodes ending with the narrator saying his catchphrase differently: "And so, once again, the day is saved, thanks to the all-binding, all-powerful, all-encompassing legal system!"
- Steven Blum voices the architect. He was voicing TOM (more specifically, TOM 3) on Toonami at this time, and Powerpuff Girls aired on Fridays on the block until 2004.