I used to love reading the DC Comics Showcase Presents black and white reprints. True, Silver Age comics take a certain amount of getting used to, and the science in them should always be taken with a grain of salt, but there was a charm to a lot of those old stories, and getting 500 pages worth of comics for under $20 was a good bargain. In the long run, it introduced me to a lot of weird or obscure characters that have appeared in a number of these columns over the years, sometimes with a “what were they thinking/smoking when they came up with THAT?!?” sort of thing.
But lots of superheroes in the old days had forgotten sidekicks, and that includes the Martian Manhunter. He had Zook.
It’s important to remember that unlike a lot of members of the Justice League, J’onn J’onzz did not have a solo series of his own until maybe the 90s. Heck, he wasn’t even that big a League mainstay for a while, being the first member to quit active duty and only coming back for the “Detroirt” era. Aquaman had more solo runs than J’onn J’onzz did. Heck, you could argue J’onn doesn’t even have an archenemy. True, his various solo works did give him opponents, but few that are all that memorable in the grand scheme of things.
As such, J’onn mostly appeared as a back-up feature in series like Detective Comics. And it was in one such story where J’onn met Zook. The case involved a quartet of beings appearing from another dimension. Two were criminals. One was the cop after them. And then there was Zook. Zook was a bit cliumsy, referred to as a sort of animal even though he could talk, and had a few special powers. Namely, he could shapeshift somewhat, mostly by flattening himself to fit through cracks or maybe stretch himself out from time to time. He could also generate intense heat or cold at close range, and his antenna allowed him to see though any disguise no matter how good a shapeshifter he was dealing with. Since there were alien criminals involved, J’onn J’onzz came along to deal with them, and when it was over, Zook managed to stay behind when everyone else went back to their home dimension.
That suggested J’onn was stuck with the little guy. He took Zook back to his secret base in a closed off cave. Zook could fit through the cracks to slip in and out while J’onn could just pass through the solid walls like a ghost. And then two would go out on cases together. This was the Silver Age. Plenty of heroes had odd sidekicks. Odd sidekicks went back to the Golden Age too, and many of these sidekicks are today more or less forgotten, especially the comic relief ones.
That said, on a more personal note, as sidekicks go, I didn’t mind Zook. Yeah, he may not have been the most effective of sidekicks and he wasn’t particularly funny, but he had a unique set of powers distinct from J’onn’s own, and he was useful to the Manhunter when he had to be. There are far worse sidekick characters…like Sergeant Rock’s.
In more recent years, Zook pops up very sporadically. During a Superman/Batman storyline where an alien force was brainwashing alien heroes and villains to attack the Earth (save for Superman), Zook managed to hold his own for a bit against both Batman and Superman before they figured out who it was, so apparently, in that story, Zook’s old appearances were still canon.

And over on the live action Supergirl TV series where the Martian Manhunter is one of Kara’s closest friends and allies, an episode mentioned how Zook was his imaginary childhood friend.
So yeah, Zook. He was almost the 300th entry in this series.
Maybe next week, I’ll do my first villain write-up.
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