Mr. Mxyzptlk has been confirmed to make an appearance on Supergirl for two episodes this season. His first appearance will be in episode 13.
Mr. Mxyzptlk is a powerful “fifth-dimensional imp” who spends much of his time spreading mischief and mayhem against heroes such as Superman. Much like the Archangel Gabriel from the CW’s Supernatural, Mr. Mxyzptlk uses his powers to change the fabric of reality in order to amuse himself at the expense of anyone in the area. So when Mr. Mxyzptlk is in town don’t be surprised if an army of stuffed animals makes war against the townsfolk.
According to the comic mythology of the character, he only makes his way to the DC Universe every once and awhile, and can only be sent back to his own realm if he is tricked into saying or writing his name backwards. By doing so he is forced to return home until he is able to make another appearance.
Mr. Mxyzptlk was created in 1944 by writer Jerry Siegel and artist Ira Yarborough. Mr. Mxyzptlk has previously appeared in The Adventures of Superboy, Lois & Clark: The New Adventures of Superman, and Smallville.
Supergirl airs Monday nights at 8 p.m. ET/PT on The CW. New episodes will return in January. There is no known date yet for the episodes which will feature Mr. Mxyzptlk although EW reports that it’s possible he might appear during the Supergirl/The Flash musical crossover.