Anti-Cosmo and his fellow Anti-Fairies are released when Timmy foolishly wishes them out. Anti-Cosmo and his wife Anti-Wanda introduce themselves to Timmy before dubbing him as the hero that released them. Timmy luckily draws out all the Anti-Fairies with lots of bad luck and tricks them into going through the door that leads back to Fairy World. Jorgen then proceeds to lock the Anti-Fairies back up into their imprisonment.
Due to Cosmo'sfagiggly gland going bad, he will need a transplant in order to continue his job as godparent. This is the direct opposite of Anti-Cosmo whose fagiggly gland is going good. Since Jorgen hates both Cosmo and Anti-Cosmo, he refuses to let Anti-Cosmo out of prison. After a couple of attempts (which almost all of them failed, and one thanks to Anti-Wanda), the trio are able to get Anti-Cosmo out in order for Cosmo to get his transplant. It works, but Anti-Cosmo escapes, but we then find out part of Cosmo and Anti-Cosmo's personalities had been transplanted to each other during the transplant.
After Anti-Cosmo noticed that his wife has strange cravings, twitching stomach and finally anti-barf he realized that Anti-Wanda is pregnant and is going to give birth to new Anti-Fairy Baby. He named his soon Foop (he thought that this sounded much better in his head) and forbid Foop going to destroy Poof and for that he was zapped. He was also zapped because he told Anti-Wanda not to tell Foop about nearest magical power source. Later he and the other Anti-Fairies were turned into care fairies and he was mad at him for that. But at the end of episode, he was turned back into an Anti-Fairy thanks to Foop's crying. Later, he and Anti-Wanda came to Abracatraz to help Foop get out from the prison.
Anti-Cosmo and Anti-Wanda are trying to steal brownie recepie that belongs to Nana Boom Boom to win annual bake-off. After they saw that Timmy accidentally downloaded it to his brain, they capture him and try to extract the recepie from his brain to win the bake-off and make that Anti-Fairies have all godchildren. At the end, it turns out that they capture Cosmo disguised as Timmy and Anti-Wanda wasn't smart enough to realize that the recipe she found had no ingredients.