Mr. Mxyzptlk is one of the non-playable characters in LEGO Dimensions 2: The Rise of Enoch, from the DC Comics franchise.
Mr. Mxyzptlk (pronounced mix-yiz-pit-lick) first appeared in Superman #30 (September 1944). He is usually presented as a trickster, in the classical mythological sense, in that he enjoys tormenting Superman. In most of his appearances in DC Comics, he can be stopped only by tricking him into saying or spelling his own name backwards (Kltpzyxm - "kel-tip-zix-um"), which will return him to his home in the 5th dimension and keep him there for a minimum of 90 days. However, this specific limitation of the character has been eliminated since the Crisis on Infinite Earths reboot, upon which the character leaves only when he willingly agrees to do so after meeting some conditions he sets, such as having Superman succeed in getting Mxy to paint his own face blue. Due to being a 5th dimensional being, he has various magical powers, such as flight, energy projection and reality warping.