The news came courtesy of a photo taken by the Canadagraphs Twitter account.
Gadiot is the latest actor to play the role previously portrayed in live action by actors Trent Ford and Michael J. Pollard. In the comics, when his name is said backwards, he disappears faster than Once Upon A Time in Wonderland did.
You can see the Canadagraphs Tweet complete with a picture of the actor with Melissa Benoist below. Supergirl returns with new episodes Monday, January 23 on The CW.
#Supergirl star Melissa Benoist & guest star Peter Gadiot as Mr. Mxyzptlk share a laugh between scenes yesterday. pic.twitter.com/OrrPnOaqiO
— Canadagraphs (@canadagraphs) January 6, 2017