Your PRANKSTER'S GAMBIT plunges to an all time low. You cannot hope to defeat Egbert in a prank-off. He is simply the best there is.
A guy (or girl) who loves practical jokes more than just a friend, and will not be selective about who they choose for a target - in fact, a success record with as many people on it as possible seems to be one of their life goals. They will be the constant annoyance of their friends, albeit humored and tolerated, akin to the Lovable Rogue. Using their tricks against the villain will usually be their Crowning Moment of Awesome that makes you forgive them for the rest.
Occassionally someone would decide to teach the prankster a lesson and give him a taste of his own medicine, which will often expose him as a hypocrite who is unable to laugh at himself (although there are genuine jokesters who enjoy a good joke even when it is on them), but note that more than one practical joker on the block for any longer duration will quickly lead to an Escalating War.
Usually there will be at least one episode where the prankster's behavior ends up backfiring on him - maybe they go too far and actually harm someone or they are thought to be joking even when they are not. Having the prankster lose his trademark behavior is a clear sign that your story had just become Darker and Edgier.
- Satoko Hojo. She is practically the master of pranking.
- The Narutaki twins and Misora in Mahou Sensei Negima.
- Tomoya Okazaki of Clannad starts off as a bit of a prankster, but grows out of it as he matures. His ability to keep a straight face while telling outrageous lies is nothing short of amazing.
- Merry and Pippin are this in The Official Fanfiction University of Middle-Earth. They're called "the Urple Bandits".
- Socrates from Calvin and Hobbes: The Series.
- Harry Potter's Fred and George Weasley.
- As well as James Potter and Sirius Black, who were directly compared to the Weasley twins. Remus Lupin and Peter Pettigrew too, to an extent.
- The Lord of the Rings's Merry and Pippin are sometimes described like this. The Official Fanfiction University Of Middle Earth is a prime example; they become the Urple Bandits and douse everyone's stuff in Urple paint (Urple being an eye-burningly horrible colour).
- Legs Mortimer, in P. G. Wodehouse's "A Farewell to Legs", and the members of the Drones Club in other stories. (Mortimer Mouse in "Mickey's Rival" may have been inspired by this story.)
- Lest you think only the Drones have this quality, mention should also be made of Roberta "Bobbie" Wickham, who, when it comes to pranking, is More Deadly Than the Male.
- Pumuckl, the kobold protagonist of a German children's series.
- Andrusch in Krabat.
- Ewan from Fire Emblem: The Sacred Stones.
- Yuffie Kisaragi of Final Fantasy VII fame.
- Luciana and Emilia in Blaze Union. While we do get a list of pranks they've pulled off, we never see them at it directly, so it can be called an Informed Attribute.
- Star Control 2 has an entire race of these with the Umgah.
- In Homestuck, John is described as the best prankster there is. But he regularly gets trounced by his Nanna, and both revered her adoptive father, Colonel Sassacre, as a master prankster. Post-Scratch, Jane and her famous Poppop share the same qualities. Since they're John & Nanna after switching places in history.
- Dangerously Chloe has Pandora, Chloe's "best friend" from the all-succubi school. One bonus page was named simply "prankster". Pandora pranks people like breathes, seems to consider it her right to the same degree and can go very far. What makes it worse is her excessive enthusiasm at anything she does. However, her friends put up with Pandora because she's fun, hard-to-get-angry-at sort... and because she is equally enthusiastic - and equally devious - at helping whenever someone whom she happens to like (and/or to whom she consider herself indebted) is in a serious trouble. And has great practice at getting out of troubles, of course.
- In Real Life, Hermann Otto Fegelein was an S.S. officer during World War II and the personal adjutant of Heinrich Himmler, who tried to defect a few days before Germany surrendered, but was caught and executed for treason. However, once he was depicted in Downfall, Fegelein started to gain a new reputation in the parodies, where he is a ruthless prankster who performs all kinds of hilariously cruel antics against Hitler. Even better is that he somehow keeps avoiding capture due to the incompetence of Hitler's staff, and whenever he is found he is literally able to cheat death and come back.
- There's also Heinrich Himmler, who is among many "Grand Masters" of antics, and he is Fegelein's mentor.
- A number of other pranksters exist in the parodies. Aside from Fegelein and Himmler, Traudl is occasionally shown performing antics. The Stalin Parodies see Joseph Stalin's general Mikhail Tukhachevksy performing all kinds of bizarre antics. While the U-Boat Parodies only have one official antic master, they still turn the entire cast of Das Boot into Loveable Rogues.
- Jokey Smurf on The Smurfs and his exploding gift boxes (although he has come up with other pranks on occassion).
- Horace from Mickey Mouse fame.
- Reggie Mantle was treated this way on The Archie Show. He would attempt to prank Archie, and inevitably some authority figure would spring the trap instead. "Mrs. Grundy!"
- My Little Pony Friendship Is Magic sees Pinkie Pie and Rainbow Dash bonding over pranks. Interestingly, rather than the usual route of having them learn that "all pranks are bad!", it's made clear that their jokes are all done in good fun, and they back down from pranking one of their friends who they think is too emotionally fragile to just shrug it off.
- T.J. Detweiler from Recess. King Bob was one as well, at least before he became the playground's king.
- Far too many spooks and spies to list, due to the necessity to keep a quick wit and a nature for deceit, have reputations as pranksters. One notable intelligence officer was Reginald V. Jones, who was the driving force in the radar countermeasures battle during the Blitz, responsible for jamming, spoofing, and otherwise playing merry hell with German communications, navigational, and radar gear. He also had a reputation as an incorrigible prankster before the war.