Trivia
- His hair is the same style as Timmy Turner, except that it's colored green instead of brown.
- Cosmo was originally designed as a fat bald lazy slob, a cross between Homer Simpson from The Simpsons and Fred Flintstone from The Flintstones. He was given a black tie to look like he was "always going to work" and to add to the show's 1950's feel.
- Cosmo is named after Cosmo Anzilotti, an animator that worked with Butch Hartman in Hanna-Barbera during the 90s. [1]
- In the original series, he and Sparky are the only main characters to never wear Timmy's hat (Timmy wear the hat almost every episode, Poof in "Sooper Poof" (since he was adopted by Timmy's parents) and "Beach Blanket Bozos", and Wanda in "Tons of Timmys").
- In the earliest shorts, Cosmo had a deep, suave voice, like a used-car salesman (described by Daran Norris, who in the documentary I Know That Voice likened the original voice to a bad imitation of comedian Phil Hartman), and was less moronic, and he and Wanda were both relatively careless and bubbleheaded ("We're two halves of a whole idiot!"). This as since changed, as over the course of the show Cosmo's changed from one half of a fairly goofy couple to the main source of carelessness and trouble, while Wanda's changed into a more sensible character.
- Prior to the birth of Poof, he was the last fairy to be born, due to the destruction that he had caused as an infant.
- Cosmo and Wanda are the only known Fairy Godparents to have two Godchildren at the same time, though it's implied that since there's a shortage of god fairies that there are others as well.
- Both Tammy and Tommy Turner are their Godchildren in the future seen in Channel Chasers.
- Before he married Wanda, Cosmo was going to ask the Tooth Fairy for a hand in marriage.
- He once bet Juandissimo Magnifico to Wanda for a nickel, which he apparently likes because of its luster. In another episode, he finds a nickel and names it Philip. Phillip is a girl nickel.
- Later, in the episode "Rags and Riches", Cosmo finds another nickel, naming it Lillian.
- Cosmo is younger than Wanda, according to "Fairly OddBaby", as he was the penultimate baby born in Fairy World.
- He is the brother-in-law of Blonda Fairywinkle, Wanda's twin sister.
- The romantic relationships between Cosmo and Wanda are similar to those of Homer and Marge Simpson from The Simpsons, which Butch Hartman himself is fan of that show.
- He doesn't like the hunt.
- He keeps his own diary, just like Vicky. Which both were revealed in A Bad Case of Diary-Uh!.
- There's been several instances he has no brain, but somewhere he has a really tiny one, as shown in the first power hour in the original series. But his head is also full of grape jelly, dancer was dancing on his brain one time, and sometimes, elevator music can be heard playing from his head.
- He's got a pet hog named Steve that lives in his pants.
- In the original cartoon, featured in 'Oh Yeah! Cartoons', Cosmo was actually smart.
- Several instances (his name, his name in Timmy the Barbarian) refer to the name Julius.
- His name in Greek means "world".
- He supposedly wears a diaper. He has been seen wearing underwear most of the time, but after Fairly Odd Baby, he was seen wearing diapers throughout the show.
- All of Cosmo's pets are named from Jimmy Neutron Characters (Carl the Ant, Cindy the Bee, Jimmy the Cat).
- He often flirts with other female characters he deems attractive (e.g. Tooth Fairy) which often angers Wanda. He has also fallen for Princess Mandie, Blonda, his reflection, a doll that was later transformed into Tootie, & various others.
- He is the only fairy to go through an on-screen Fairy Pregnancy.
- He likes rice, pie, corn, lemonade, pudding and churros.
- His favorite flower is the rose as revealed in the video game, "Shadow Showdown".
- Cosmo's old band is called The Fairies. It consists of himself on the electric triangle, Eric Clapton on the guitar, Pan on the pan flute, Santa Claus on drums, and Ludwig van Beethoven on the organs.(They were seen in Boys in the Band)
- Cosmo, along with Wanda, appears in "The Fairly OddParental Controls", a parody of "The Fairly OddParents" in "MAD".
- Cosmo is allergic to nuts, revealed in the "Squirrely Puffs" episode, although in past episodes he has been seen eating nuts without allergic reactions. The nuts he ate in Squirrely Puffs may have been a special kind of nuts that he is allergic to or that Cosmo takes a medication to prevent having an allergic reaction to nuts.
- He is apparently the reason why Denzel Crocker lost both him and Wanda due to allowing himself to be revealed to humans.
- He is a distant relative of the Von Strangle family, according to the episode, "Cosmo Rules".
- He is scared of words.
- Darran Norris who voices Cosmo also voices over many male characters of the show including Timmy's Dad, Anti-Cosmo and Jorgen von Strangle.
- Cosmo's brain is probably located in butt according to Balance of Flour but other episodes strongly disagree with this.
- According to the episode, "The Gland Plan", Wanda stated that Cosmo was an only child but in the episode, "Double-Oh Schnozmo" his brother Schnozmo visits.
- In "Betty and Veronica", it's revealed that Schnozmo paid Dr. Rip Studwell to erase his name from Cosmo's medical record.
- Cosmo seems to have gotten most of his appearance from his long lost father, Papa Cosma.
- Cosmo and Wanda have been married to one another for nine thousand eight-hundred ninety five years.
- According to A.J., Cosmo looks way smarter than Timmy's Dad.
- He has called Timmy sport apparently two times in the original series.
- During his role as a temporary villain in The Really Bad Day!, Cosmo sported a goatee on his chin and went by the name "Cosmean" for the time being.
- His favorite color is bleach (App Trap) and green (Where's the Wand?).
- Cosmo, along with Wanda, appeared in Ned's Declassified School Survival Guide episode, "Daydreams".
- He, along Mr. Turner's intelligence had been decreased since Season 6.
- In Cosmonopoly, Cosmo's height is 2'2 although in Turning Into Turner, he is 3'6.
- It is also revealed in Turning Into Turner that Cosmo doesn't weigh any pounds.
- Cosmo is highly allergic to potato chips and nuts.
- In Tons of Timmys, it is revealed that Cosmo does not have a birthmark on his butt.
- In A Sash and a Rash, it is revealed that Cosmo is allergic to peaches.
- In The All New Fairly OddParents! Cosmo and Wanda's relationship were somewhat retained from the early seasons relationship (before they were flanderized) as lovely couple of husband and wife, who despite their differences, love each other, making Cosmo still not so bright character but he can came with smart decisions, while Wanda became less of nag.
- Cosmo is the last character to speak in the series finale in The Fairly OddParents: The Next Generation.