This isn't a great cover for a lot of reasons, but ones specific to Zook include pushing a diminutive figure too far into an obscuring background and making an already problematic pidgin-speaking caricature even more cartoonishly ineffectual with the head shaking.
5) House of Mystery #148 (January, 1965)
Anyone else hear Micky Rooney in yellowface delivering that dialogue? Still, it's the only cover to offer true Zook-speak, and the balloon helps make you aware that he's there, even if the framing and angle of the image leave a lot to be desired.
4) House of Mystery #151 (June, 1965)
Zook is arguably as visible as his partner, but is still whining instead of using his own powers to help. Admittedly, Zook always fretted before taking action, but then stepped up, which isn't reflected.
3) House of Mystery #145 (September, 1964)
The only Zook cover where he's on model, to scale, and working within his established role (though still needlessly distressed.)
2) House of Mystery #147 (December, 1964)
Here, Zook demonstrates one of his signature powers, elasticity, while taking up more cover space and punching his master/mentor/pal in the jaw. Hey, sometimes negative attention is better than none at all.
1) House of Mystery #143 (March, 1964)
Besides being easily the most prominent Zook frontpiece to date, this was also my #1 Martian Manhunter cover of the 1960s overall. It was the start of the pair's series of strips after moving out of the Detective Comics back-up spot into cover featured star status (for nine non-consecutive issues, anyway.) Even the Idol-Head of Diabolu got a mention!