Planet of the Moms is a planet Timmy has wished up in Invasion of the Dads. At the end of the episode, all the dads started crying because Timmy's mom left. Timmy however wished this planet up to make them happy as well as prevent them from trying to take his mom away again.
The planet looks more similar to Planet of the Dads. However it is shaped like Mrs. Turner' head, it's yellow and it's filled with clones of Timmy's mom.
Gallery
The planets of the Dads and the Moms
The dad clones celebrate as the planet of the moms got wished up.