Cosmo Julius Cosma is one of the main characters on the show. He is one of Timmy Turner's fairy godparents alongside his wife, Wanda and his son, Poof. Cosmo is one of the dumbest characters on the show, rivaled only by Timmy's Dad, and his ideas are what often lead Timmy into trouble. He is sometimes a bit over-emotional. Cosmo is voiced by Daran Norris in the cartoon, who also voiced the CGI (3D) version of Cosmo in the live action "Fairly Odd Movie" and its sequel. A humanized version of Cosmo also appeared in the live movie, played in live action by Jason Alexander.
Cosmo is Timmy Turner's current 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 lack of intelligence, 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 low I.Q. 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 eventually would have a child together named Poof.
He is the younger son of the overprotective Mama Cosma, who did not approve of his marrying Wanda Fairywinkle-Cosma in the least bit and has often tried to separate the two. He was once the last Fairy ever born, as his birth caused the ban of fairy babies, until Poof came. He apparently also was in a band where he played the electric triangle, though tomatoes were thrown at him every time he has played.
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 is usually the cause behind Timmy's crazy adventures, often misunderstanding circumstances, or agreeing to grant a dumb wish. He will sometimes cause Timmy to realize what has to be done to reverse a wish, but this does not happen often. He keeps a diary, which has all of his deepest, darkest secrets, including the fact that he is afraid of the hunt. He is often the subject of magic from Wanda, who usually does something to him to shut him up, including zipping his mouth, and then encasing him in vanadium.
There are countless other scenarios. He is often rather careless, but loves Wanda and Timmy Turner through his destructiveness. Cosmo is noted to be one of the most powerful fairies ever, seeing as he blew up all of Fairy World in the first 5 seconds after he was born, sunk Atlantis 9 times, destroyed Fairy World again 5 times, caused Mt. Vesuvius to erupt and destroy Pompeii, transformed Xanadu into Pittsburg, summoned up a gigantic three-headed hydra, whom he dubbed "Snowball", with one careless wave of his wand, and was able to accidentally wish away Wanda's wand and make wands in Wishology, which is something that it is said that fairies cannot do when they say that magic cannot wish away magic.
Cosmo also has had a big crush on the Tooth Fairy in some episodes but yet never had a chance to show it because she is in a relationship with Jorgen. Cosmo is also very ticklish.
While pregnant with Poof during Fairly Odd Baby, Cosmo experienced severe mood swings so much so that his temper even scared Wanda and Timmy. In Lights Out, he even went along with Wanda's plan to get back at Timmy who had scared Poof after reading the young fairy baby a scary story.
He seems to have an obsession over most food especially red meat (bacon, weiners, ham etc.). Almost every time he is seen with food it is exaggerated. It has even become a running gag in the series. The first time he was seen to love red meat was in Hard Copy with bacon as he could not resist it when Wanda made it. However, there are a few food he doesn't like. They include beets and sauerkraut.
Cosmo's intellect, or lack of thereof, is often a source of many of the disastrous wishes that happen on the show. His head is quite literally empty and has no brain inside to speak of. According to "Fairly Odd Baby", his head is completely full of jelly. He will either misinterpret a wish completely, ignore a rule or plot point which would prevent the wish from easily being unwished, or outright wish-grant the wrong thing that leads to trouble for Timmy. In earlier episodes, Cosmo and Wanda usually split some of the blame, being "two halves of a whole idiot", but in later seasons it is usually just Cosmo being irresponsible that leads to chaos. In some rare cases, especially in a few Season 7 episodes, Cosmo shows brief and uncharacteristic bouts of knowledge when is able to guess or summarize the plot of an episode without any other character knowing what is going on. It can also be argued that since giving birth to Poof, Cosmo has started to mature little by little as he learns to be a father. In the early "Oh Yeah! Cartoons" shorts, Cosmo was considerably more intelligent (and Wanda less intelligent) than how he would later be in the show. Cosmo has a strange obsession over a Nickel whom he named Philip, which adds more stupidity to his character since he stated Philip was a girl nickel.
Ever since the day Cosmo was born, he has been causing chaos. When he got a magical rattle, he accidentally used it to turn Jorgen into a bomb that blew up all of Fairy World. The second he got old enough to receive his first wand, he turned his father into a fly, never to be seen again. When Cosmo turned five, Mama Cosma put him in art classes. Instead of painting, he caused an explosion that took out half the class while making a exploding daisy. Later on, because of his dangerous lack of control over his magic, his mother sent him to the Fairy Godparent Academy much to Cosmo's distress, where Jorgen Von Strangle, who at the time, a 5-star commander in the Fairy Academy, taught him as well as many others. Cosmo has then been known as the worst thing to happen to Fairy World everywhere. Examples include: when fairies learned accuracy with their magic and turned flying plates into birds and butterflies, he turned his plate into a destructive hydra that he named "Snowball", which became his new pet, and while fairies discovered the strange place of Atlantis, Cosmo sunk it 9 times, gaining the nickname "The Accursed One". This caused Jorgen to lose his stars and gained a strong despise of Cosmo.
After graduating with the worst results, he became a full-fledged fairy, and sunk Atlantis another eight times. The amazing and unbelievable chaos and destruction Cosmo caused in his life made the Supreme Fairy Council have Jorgen add a new rule to Da Rules that would forbid the birth of any more Fairy Babies, making Cosmo the last Fairy ever born, until Timmy wished they had a baby and Poof was born (Jorgen wrote the rule on a sticky note but never officially put it in). Because he was so disaster-prone, nobody wanted to be around him, turning him into an outcast who was bullied by everyone, even the nerds. While he was working at a fast food restaurant, he met Wanda, which happened to be love at first sight, proposed to her with a chewed pen cap, and they later got married. But, according to Nick.com's short Cosmo's Baby Book, Cosmo and Wanda first met when they were babies. It's possible that since they were babies, Cosmo and Wanda forgot about their meeting and met again at a restaurant years after their first meeting.
Cosmo's family includes his mother, the overprotective Mama Cosma, and his father, Papa Cosmo, who he turned into a fly. He also has an unseen grandfather, Grandpa Gonzo. His wife is Wanda Fairywinkle-Cosma (who Mama Cosma hates), his son is Poof and his current godchild is Timmy Turner. He also has an older brother called Schnozmo (although earlier on in the series, Wanda said that Cosmo was an only child). Recently, Mama Cosma has not been as mean to Wanda, possibly implying that since Poof was born, they had a truce.
About a year or so after receiving Cosmo as his fairy godparent, Timmy wishes that Cosmo and Wanda would have a baby together in hopes that they would become happier. Due to the awkward way that Fairy Pregnancy works, Cosmo was the one who became pregnant (instead of Wanda). He began to throw up purple goo everywhere, had strange mood swings and cravings, and his belly became big and round. Although the Pixies and Anti-Fairies were plotting to steal Cosmo and Wanda's baby away, they did not succeed, and Cosmo and Wanda welcomed a son named Poof into their family.
In the film, Cosmo and Wanda try to put a stop to Timmy's budding relationship with Tootie, because if he falls in love with her, he will lose his fairies forever. At one point, Cosmo and Wanda transform themselves into humans in order to disrupt Timmy and Tootie's date.
After Tootie is captured by Hugh J. Magnate Jr., Cosmo and Wanda initially decide to not rescue her, so that they can stay with Timmy, but Poof gives them an "intense stare of guilt" and brings them to realize they've been doing the wrong thing. They are then suddenly captured by Mr. Crocker and placed in his Atomic Fairy Incarcerator, where their magic is rerouted so that are forced to grant Magnate's wishes, which also slowly drains their life force. However, Timmy manages to save them by confessing his love to Tootie and passionately kissing her, which causes him to officially lose his fairies due to him having now officially grown up, but also frees them from Magnate. In the end, because of how much Timmy loved them, though, the Fairy Council adds the Timmy Turner Loophole to Da Rules, allowing Cosmo, Wanda, and Poof to stay with Timmy into his adulthood, and with Tootie allowed to know of their existence as long as Timmy uses their magic to help people and not for his own gain.
In Channel Chasers, it is shown that he and Wanda will become fairy godparents to Timmy (and presumably Tootie)'s future children Tammy and Tommy.
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 to have no true intention, 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 about ten thousand years.
Despite their contracting personalities, and their tendencies to argue, they stay married and have a good relationship. Wanda usually acts as the mind (and the bravery) while Cosmo acts as the fun. Cosmo often regards Wanda as a nag and neglects her words, sometimes even when they are in his favor.
In some cases, Cosmo's stupidity rubs off the wrong way on Timmy , and he is usually the one causing Timmy to make a bad wish when Wanda is advising against it. Cosmo and Timmy share more of a buddy relationship rather than a father-son relationship.As seen in the episode "Fly Boy ",Cosmo and Timmy both disobeyed Wanda telling them they can't see the movie,"I Was a Teenage Blowfly". Despite falling for Cosmo's ideas, Timmy is usually well aware of how intelligent Cosmo really is, but if it sounds fun enough Timmy will go with it anyways.Usually, Cosmo's the one who encourages Timmy to make a dumb wish, or its's his idea.
Cosmo and Poof have a good relationship like a young father and infant son would have. Poof refers to Cosmo as "Dada" and somewhat recognizes his father's stupidity, but loves him with all his heart. Whenever Cosmo and Wanda get taken away from Poof, he starts to cry and will be stopped by Timmy making faces to him
Jorgen often bullies Cosmo, as he does everyone, and Cosmo shows fear of Jorgen. In "This Is Your Wish", it is revealed that Jorgan holds a large amount of animosity toward Cosmo for ruining the lives of (and possibly killing) many people, causing much chaos, and ruining civilizations countlessly during his time at the Fairy Academy, in which Jorgen acted as his drill sergent. Since then, he has been acting out revenge by tormenting Cosmo and his wife, Wanda. Whenever he remembers the events, he is shown in a rare site of pity and regret, until bursting with anger towards Cosmo. Cosmo's constant overimaginated stupidity caused Jorgan to create a new rule focusing on Cosmo by keeping from the birth of anymore fairies that could be like Cosmo.
Despite this, Jorgen enjoys the company of Cosmo rather than Wanda. In several episodes, Jorgan blames Wanda for is clearly Cosmo's fault, and refers to him as a bottle of disaster waiting to happen every second. In current episodes, they get along much better.
Cosmo and Sparky
He has a really great relationship with Sparky. He apparently has fleas and bite on his butt like Sparky on Fairly OddPet. They sometimes cause havoc together.