Anti-Fairy World is the homeworld of the Anti-Fairies Anti-Cosmo, Anti-Wanda and Foop (its most noteworthy residents) live in Anti-Cosmo's Castle.
Unlike Fairy World, which is bright and pink with a colorful purple sky, Anti-Fairy World is dark and blue with a blood-red sky. The Anti-Big Wand and other buildings in this world are twisted and vile looking. The ruler of this world is Anti-Cosmo, who resides in a giant Gothic-looking castle.
The clouds that Anti-Fairy World resides on are usually blood red and black storm clouds. All of the structures around Anti-Fairy World are twisted and evil looking. There is a purple tinted rainbow. It seems to have thorns covering it, possibly to keep other people out. The Anti-Fairy World sign is made of wood and the words are yellow, there is also chicken wire in front of it. Anti-Fairy World was briefly turned into a sweet happy world that was covered with niceness and cuteness when Foop redesigned the world for his own amusement after draining out the Anti-Big Wand's Power. It is later reverted to normal by Foop's crying along with the other worlds that Foop terrorized in his rampage. Anti-Fairy World is believed to have never been occupied for centuries as during earlier episodes, the Anti-Fairies were all imprisoned by Jorgen Von Strangle.
- Main article: Anti-Cosmo
Anti-Cosmo is the leader of Anti-Fairy World. He is smarter than Cosmo and he is the husband of Anti-Wanda. He is the father of Foop. He lives in his Castle and he makes meetings there making evil plans.
- Main article: Anti-Wanda
Anti-Wanda is the wife of Anti-Cosmo, who is the leader of Anti-Fairy World. She is not smart and she looks to eat sandwiches with her feet. She is the mother of Foop. She lives in Anti-Cosmo's Castle.
- Main article: Foop
Anti-Poof or Foop, is the son of Anti-Cosmo and Anti-Wanda. He is a little bit smart as his father. He wants to destroy Poof, because he is the second fairy baby to be born in many years and also because he does not wants to share the spotlight. He also wants to destroy Timmy Turner for defeating him in some episodes.
- Main article: Anti-Jorgen
Anti-Jorgen is one of the Anti-Fairies citizens. He is not the leader of the Anti-Fairies like Jorgen Von Strangle.
- Main article: Anti-Fairies
The Anti-Fairies are the citizens of Anti-Fairy World.
- Anti-Cosmo's castle is the place of Foop's birth.
- On the signboard, "Anti-Cosmo's Castle. Welcome-Not" is written.