Supergirl: Who Is Mister Mxyzptlk?

Supergirl has been having fun in a post-"Crisis on Infinite Earths" world, and the long-running The CW series has covered quite a lot of DC Comics ground in the process. Now that the show exists on Earth-Prime, it's dealing with the destruction and return of the multiverse in a pretty big way. If that wasn't enough, the show is headed towards its 100th episode -- which coincided perfectly with the newest character return. Spoilers for tonight's episode of Supergirl, "Back from the Future: Part Two", below! Only look if you want to know!

Towards the end of the episode, Kara Danvers/Supergirl (Melissa Benoist) was greeted by Mr. Mxyzptlk (Tom Lennon), the 5th Dimensional Imp that she had crossed paths with years ago. He gave her the opportunity to revisit some key moments in her time as a superhero, something that she had just been wondering if she could do.

Mxyzptlk was created to appear in 1944's Superman #30, but ultimately made his debut in Superman's daily comic strip. Mxy had the ability to warp reality to his will, which he used to harass and annoy Superman many times over. In the majority of his appearances, he can only be banished back to the Fifth Dimension after he is tricked to say or spell his name backwards. This was slightly shifted in the post-"Crisis" comics, as he was only able to leave after meeting an incredibly specific set of conditions.

Mxy last made an appearance in Supergirl's second season, when he was portrayed by Once Upon a Time in Wonderland actor Peter Gadiot. This iteration of Mxy had fallen in love with Kara after watching her from the Fifth Dimension, and began to challenge Mon-El (Chris Wood) for her affections. Through a chain of events, Kara pretended to accept Mxy's marriage proposal, ultimately leading him to the Fortress of Solitude and convincing him to type his name backwards in Kryptonian.

Given Mxy's ability to manipulate reality, the fact that he's able to don a different face from his Season 2 appearances isn't much of a surprise. Still, it will be interesting to see if and how "Crisis" has affected Mxy in next week's episode and beyond -- and to see Lennon bring the one-of-a-kind character to life.

Supergirl airs Sundays at 9/8c on The CW.