Cosmo is Timmy Turner's fairy godfather. Along with his wife, Wanda, he was tasked with making miserable human children happy by granting them wishes and keeping them safe. Unfortunately, due to Cosmo's immense stupidity, he often times puts Timmy in danger with his wishes, or misinterprets the wording of a wish and grants it wrong, wreaking havoc. Despite his stupidity, and a tenancy to argue with Wanda, he really does love his wife and his godchild. He often goes along with Timmy's wishes unlike Wanda who is a little strict about them. He and Wanda have a child together named Poof.
Cosmo has green hair, green eyes, and wears a white shirt with a black tie, and black pants and shoes. Like all Fairy Godparents, he has a magic wand, fly-like wings which allow him to float, and a crown floating above his head. Cosmo seems to have gotten most of his appearance from his long lost father, Papa Cosmo.
Cosmo and Wanda is considered the official pairing of the show, and has countless episodes and merchandise which support it. Cosmo is shown to love and care about his wife very much. In some episodes, this is inverted, and Cosmo seems to dislike Wanda or want to escape from marriage, but this is almost universally considered bad writing by fans, and has never had a long-term effect on their relationship in the series.In some episodes, Cosmo always defends Wanda and gets jealous from Juandissimo.This proves that Cosmo really loves his wife and always will. Cosmo and Wanda met when they were teenagers; Cosmo was a nerd that worked a diner, and Wanda was a popular girl. Cosmo proposed to Wanda with a chewed pen cap. They eventually got married, and have been so for thousands of years.
His hair is the same style as Timmy Turner, except colored green instead of brown.