In a clip from tonight’s episode of Supergirl, we see the team sitting around Kara’s (Melissa Benoist) apartment along with M’rynn (Carl Lumbly), when he shares a story of things J’onn (David Harewood) would do as a child and then blame on his imaginary friend Zook. After a good laugh at the revealed name, Alex (Chyler Leigh) gets a warning alert and Kara slowly unbuttons her shirt instead of ripping it open to everyone’s surprise… seems this is one of her favorite shirts.
As funny as the shirt joke is, the bigger thing here is Zook. M’yrnn refers to Zook as an imp from the 5th dimension, but he was actually a comic character created in January 1963 by Jack Miller and Joe Certa in the pages of Detective Comics #311. In the story four creatures cross over to Earth from a parallel dimension. Two of the creatures were ciminals, the third on a mission to stop them and the fourth was different from the others and best described as ‘a mischievous little animal’. This, of course, was Zook. Martian Manhunter got involved with the aliens, eventually capturing the two with Zook’s help and sending them back through the closing portal. All except Zook who J’onn ended up keeping as a pet
Zook was the Martian Manhunter’s equivalent to Bat-Mite and Mr. Mxyzptlk.
He popped up more recently in an issue of Superman/Batman as one of the aliens living on Earth being controlled by an invading force. Zook has the power of shapeshifting and power replication.
Supergirl airs tonight at 8 PM on the CW.