N-Zs are common enemies that appear only in Kirby 64: The Crystal Shards. They replace Waddle Dees because the single Waddle Dee that appears in that game is one of Kirby's friends. N-Zs are just as easy to defeat as the Waddle Dees in other games.
N-Zs are dark gray balls with round black eyes, pointy cat-like ears, and white shoes. They give no copy abilities when eaten. A bigger version of an N-Z is found in Level 1-1 as a mini-boss, just two rooms before the fight with a Dark Matter-possessed Waddle Dee.
While N-Zs are very common, they are only found on Pop Star, Ripple Star, and, strangely enough, Dark Star. They are the only enemies found in Dark Star, other than the final boss, Zero Two. Because of this, it's clear that N-Zs are made out of Dark Matter.Also ther name might stand for negative zero.