The Great Whodini

Any character who is not normally a magician, but is putting on a magic show, will use a stage name formed by taking their name and appending "-ini". Often they'll prefix "The Great", as well.

Obviously the inspiration for these names is Harry Houdini, who himself based his stage name on French magician Jean Eugene Robert-Houdin, or possibly Cardini. Never mind that Houdini considered himself an escape artist, not a magician, and never presented himself as having magical powers rather than exceptional dexterity.

Not to be confused with the 80's rap group.

Examples of The Great Whodini include:

Film

Ben 10: Race Against Time had "The Great Gwendini... and her assistant".

Literature

Edgar of Edgar and Ellen demonstrated his escape artist skills as "The Great Edgarini".

Live-Action TV

Batman TV Series: In the episode Zelda the Great,they really did the research. She has a billboard that boasts: Zelda the Great: World's foremost illusionist and escape artiste, Even Greater than Houdini!.
On Home Improvement, there's an episode where the three sons each want to make a birthday present for their mother, but Randy, the middle son, isn't good with his hands, so he plans a magic show. At the end of the episode, his climactic disappearing box says "The Great Randini" on it.
One episode of MST3K had Crow as an escape artist calling himself "The Great Crowdini".
On News Radio Dave called himself the Great Throwdini for his Knife-Throwing Act. He also performed as the Great Ventriloquodini.
Magician Ricky Jay played magician "The Amazing Maleeni" in The X-Files episode of that name.

Stand-up comedy

Johnny Carson was "The Great Carsoni" as a young magician.
Invoked by Denis Leary in his stand-up routine, regarding pulling his family dog out of the toilet: "Like I'm some kinda magician, the Great Learitini..."
Steve Martin often did tricks for private gatherings involving things coming out of the crotch of his pants. His alias? The Great Flydini.

Web Comics

8-Bit Theater had Fighter reminisce about the group's (hitherto unknown) plans for a circus act, complete with a poster showing "Fightini", "Thiefini", "Red Magini", "A Cannonball" (Black Mage) and "Fightini again".
This Sluggy Freelance strip.

Western Animation

"The Great Bicklini", a.k.a. Mr. Bickles in The Fairly OddParents.